referring now to the drawings , a description will be given of the duct apparatus in accordance with the invention . the duct apparatus in accordance with a first embodiment has the above - described configurations ( 1 ) to ( 6 ) and ( 8 ). the duct apparatus in accordance with the first embodiment is installed in a console box of a motor vehicle . an exploded perspective view schematically illustrating the duct apparatus in accordance with the first embodiment is shown in fig1 , and a cross - sectional view schematically illustrating a cross section of the duct apparatus of the first embodiment taken along line a - a in fig1 is shown in fig2 . a cross - sectional view schematically illustrating a cross section of the duct apparatus of the first embodiment taken along line b - b in fig1 is shown in fig3 . hereafter , the directions associated with the terms “ vertical ” “ left ,” “ right ,” “ front ,” and “ rear ” referred to herein shall be construed to be those shown in fig1 . the duct apparatus in accordance with the first embodiment has a duct 1 , an air guiding portion 2 , and a rectifying member 3 . the duct 1 has a substantially rectangular tubular shape , and has one end portion connected to an air conditioner ( not shown ). the duct 1 extends along the inflow direction of conditioned air indicated by the arrows in fig2 . an opening portion 10 is formed at the other end portion of the duct 1 . the opening portion 10 extends in the left - and - right direction ( the inflow direction of the conditioned air ). the opening portion 10 is covered by the air guiding portion 2 which is plate - shaped . the air guiding portion 2 has a plurality of air guiding holes 20 which are arranged at equal intervals in the left - and - right direction ( the inflow direction of the conditioned air ) and in the vertical direction ( a direction perpendicular to the inflow direction of the conditioned air ). the air guiding holes 20 extend in the front - and - rear direction ( a direction perpendicular to the inflow direction of the conditioned air ) and allow the interior of the duct 1 and the outside to communicate with each other . in the duct apparatus in accordance with the first embodiment , the respective air guiding holes 20 extend parallel to each other . the plate thickness of the air guiding portion 2 is 3 . 0 mm . the respective air guiding holes 20 are formed in the same shape , and the opening of each air guiding hole 20 has the shape of a regular circle . each air guiding hole 20 has an opening diameter of 5 . 0 mm and an opening area of 19 . 63 mm 2 . the air guiding holes 20 are formed at intervals of 7 . 0 mm and have a real opening ratio of 40 . 1 %. the rectifying member 3 is disposed between the opening portion 10 and the air guiding portion 2 . in the rectifying member 3 , a plurality of plate - shaped guide fins 30 extending in the vertical direction ( the direction perpendicular to the inflow direction of the conditioned air ) are arranged at equal intervals , and the guide fins 30 are secured to the interior of a body portion 31 having a frame shape . the duct 1 , the air guiding portion 2 , and the rectifying member 3 are respectively formed separately , and are integrated by being secured to each other . the duct apparatus in accordance with the first embodiment is installed in a console box 5 . specifically , as shown in fig3 , a console opening 50 is formed in the console box 5 , and the duct 1 is secured to a rear surface side of the console box 5 with the opening portion 10 opposing the console opening 50 . since a seal member 6 formed of an elastic material is secured to a rear side peripheral edge portion of the console opening 50 , the duct 1 and a peripheral edge portion of the console opening 50 abut against each other through the seal member 6 . the air guiding portion 2 is disposed on the front surface side of the console box 5 , is secured to a front side peripheral edge portion of the console opening 50 , and covers the opening portion 10 and the console opening 50 . the rectifying member 3 is disposed on the rear side of the air guiding portion 2 , and a portion thereof is held inside the opening portion 10 . in the duct apparatus in accordance with the first embodiment , the conditioned air which flowed into the duct 1 from the air conditioner circulates through the interior of the duct 1 along the extending direction of the duct 1 ( the inflow direction of the conditioned air ). the conditioned air , which has circulated through the interior of the duct 1 and reached the opening portion 10 , flows out to the outside through the rectifying member 3 and the air guiding portion 2 . in the duct apparatus in accordance with the first embodiment , since the duct 1 extends along the flowing direction of the conditioned air , the turbulent flow of the conditioned air is difficult to occur inside the duct 1 . the air guiding holes 20 extend in the direction perpendicular to the inflow direction of the conditioned air , and partition the opening portion 10 into small regions . for this reason , the airflow direction of the conditioned air is guided with high accuracy along the extending direction of the air guiding holes 20 . further , since the airflow direction of the conditioned air is guided with high accuracy along the extending direction of the air guiding holes 20 , the airflow velocity of the conditioned air flowing out to the outside from the plurality of air guiding holes 20 arranged along the extending direction of the duct 1 ( the inflow direction of the conditioned air ) becomes uniform . it should be noted that , in the duct apparatus in accordance with the first embodiment , the conditioned air which reached the opening portion 10 is rectified by the rectifying member 3 , and reaches the air guiding portion 2 . for this reason , the airflow direction of the conditioned air is guided more reliably in a desired direction . in the duct apparatus in accordance with the first embodiment , the air guiding portion 2 , the duct 1 , and the rectifying member 3 are respectively formed separately , but may be formed integrally . in the duct apparatus in accordance with the first embodiment , the air guiding portion 2 is secured to the front surface side of the console box 5 , and the duct 1 is secured to the rear surface side of the console box 5 . however , as shown in fig4 , the duct 1 and the air guiding portion 2 may be fixed to the same surface ( the rear surface in fig4 ). in this case , if a console - side retaining portion 51 for retaining the duct 1 and the air guiding portion 2 is provided on the console box 5 , and a duct - side retaining portion 15 for engaging the console - side retaining portion 51 is provided on the duct 1 , the duct 1 and the air guiding portion 2 can be easily attached to the console box 5 . the duct apparatus in accordance with a second embodiment has the above - described configurations ( 1 ) to ( 4 ), ( 6 ), and ( 8 ). the duct apparatus in accordance with the second embodiment is identical to the duct apparatus in accordance with the first embodiment except for the shape of the air guiding portion . the plate thickness of the air guiding portion in the duct apparatus in accordance with the second embodiment is 3 . 0 mm . the respective air guiding holes are formed in the same shape , and the opening of each air guiding hole has the shape of a regular circle . each air guiding hole has an opening diameter of 3 . 0 mm and an opening area of 7 . 07 mm 2 . the air guiding holes are formed at intervals of 7 . 0 mm and have a real opening ratio of 14 . 4 %. in the duct apparatus in accordance with the second embodiment , in the same way as the duct apparatus of the first embodiment , since the duct extends along the flowing direction of the conditioned air , the turbulent flow of the conditioned air is difficult to occur inside the duct . the air guiding holes extend in the direction perpendicular to the inflow direction of the conditioned air , and partition the opening portion into small regions . for this reason , the airflow direction of the conditioned air is guided with high accuracy along the extending direction of the air guiding holes , and the airflow velocity of the conditioned air flowing out to the outside from the plurality of air guiding holes arranged along the extending direction of the duct ( the inflow direction of the conditioned air ) becomes uniform . the duct apparatus in accordance with a third embodiment has the above - described configurations ( 2 ) to ( 4 ), ( 6 ), and ( 8 ). the duct apparatus in accordance with the third embodiment is also identical to the duct apparatus in accordance with the first embodiment except for the shape of the air guiding portion . the plate thickness of the air guiding portion in the duct apparatus in accordance with the third embodiment is 1 . 0 mm . the respective air guiding holes are formed in the same shape , and the opening of each air guiding hole has the shape of a regular circle . each air guiding hole has an opening diameter of 3 . 0 mm and an opening area of 7 . 07 mm 2 . the air guiding holes are formed at intervals of 7 . 0 mm and have a real opening ratio of 14 . 4 %. in the duct apparatus in accordance with the third embodiment , in the same way as the duct apparatus of the first embodiment , since the duct extends along the flowing direction of the conditioned air , the turbulent flow of the conditioned air is difficult to occur inside the duct . the air guiding holes extend in the direction perpendicular to the inflow direction of the conditioned air , and partition the opening portion into small regions . for this reason , the airflow direction of the conditioned air is guided with high accuracy along the extending direction of the air guiding holes , and the airflow velocity of the conditioned air flowing out to the outside from the plurality of air guiding holes arranged along the extending direction of the duct ( the inflow direction of the conditioned air ) becomes uniform . the duct apparatus in accordance with a comparative example is also identical to the duct apparatus in accordance with the first embodiment except for the shape of the air guiding portion . the plate thickness of the air guiding portion in the comparative example is 10 . 0 mm . the air guiding holes are formed in the shape of slits extending in the vertical direction ( in the direction perpendicular to the inflow direction of the conditioned air ), and are arranged along the left - and - right direction ( in the inflow direction of the conditioned air ). the air guiding holes extend parallel to each other . the respective air guiding holes are formed in the same shape , and the opening of each air guiding hole has a rectangular shape . each air guiding hole has a vertical length of 20 . 0 mm and a left - to - right length of 20 . 0 mm . each air guiding hole has an opening area of 2000 mm 2 . the air guiding holes are formed at intervals of 2 . 0 mm and have a real opening ratio of 91 %. in the duct apparatus in accordance with the comparative example , in the same way as the duct apparatus of the first embodiment , since the duct extends along the flowing direction of the conditioned air , the turbulent flow of the conditioned air is difficult to occur inside the duct . the air guiding holes extend in the direction perpendicular to the inflow direction of the conditioned air , and partition the opening portion into small regions . for this reason , the airflow direction of the conditioned air is guided with high accuracy along the extending direction of the air guiding holes , and the airflow velocity of the conditioned air flowing out to the outside from the plurality of air guiding holes arranged along the extending direction of the duct ( the inflow direction of the conditioned air ) becomes uniform . the duct apparatuses in accordance with the first to third embodiments and the comparative example were installed in the air conditioner , and the airflow velocity of the conditioned air flowing out from the duct apparatus was measured . specifically , the velocities of the conditioned air at three points including an upstreammost side position ( position a ) in the inflow direction of the conditioned air in the opening portion , a downstreammost side position ( position c ) in the inflow direction of the conditioned air in the opening portion , and an intermediate position ( position b ) between the position a and the position c were measured at a position located on the outside opposing the opening portion . an air velocity sensor was used as the measuring apparatus . the distance between the opening portion and the measuring apparatus was 100 mm . the rate of flow of the conditioned air flowing into the duct from the air conditioner was 30 m 3 / h . the results of the airflow velocity measurement test are shown in table 1 . the duct apparatuses in accordance with the first to third embodiments and the comparative example were installed in the air conditioner , and the pressure loss at the time when the conditioned air passes through the duct apparatus was measured . the results of the pressure loss measurement test , together with the results of the airflow velocity measurement test , are shown in table 1 . as shown in table 1 , in the duct apparatus of the comparative example , the airflow velocity of the conditioned air at the position a was 0 . 8 m / s , and the volume of the conditioned air flowing out from the upstreammost side position ( position a ) in the inflow direction of the conditioned air in the opening portion in the opposing direction ( in the direction perpendicular to the inflow direction of the conditioned air ) is small . accordingly , it can be seen that , in the duct apparatus of the comparative example , the airflow velocity of the conditioned air flowing out to the outside from the plurality of air guiding holes arranged along the inflow direction of the conditioned air is not uniform . on the other hand , in the duct apparatuses in accordance with the first to third embodiments , the airflow velocities of the conditioned air at the position a , the position b , and the position c are in the range of 1 . 0 to 2 . 5 m / s , and it can be seen that the airflow velocity of the conditioned air flowing out to the outside from the plurality of air guiding holes arranged along the inflow direction of the conditioned air is uniform . particularly in the duct apparatus in accordance with the first embodiment , the airflow velocities of the conditioned air at the position a , the position b , and the position c are substantially uniform , and are contained in the range of 1 . 0 to 2 . 0 m / s . accordingly , in the case where the duct apparatus of the first embodiment is installed in a motor vehicle , and the conditioned air is blown out toward the thighs and their vicinities of the occupant by the duct apparatus of the first embodiment , it is possible to blow out the conditioned air at a uniform and gentle airflow velocity , thereby making it possible to greatly reduce the discomfort which is received by the occupant . furthermore , the duct apparatus of the first embodiment has an extremely small pressure loss . accordingly , according to the duct apparatus of the first embodiment , the airflow direction of the conditioned air can be guided reliably in a desired direction .