below the embodiment of the present invention is explained using fig1 through 10 . in fig1 ( 1 ) shows a printed circuit board which is preheated in a preheating section ( 4 ) and then supplied to a main heating section ( 5 ), where it undergoes reflow soldering ; afterwards the printed circuit board ( 1 ) is transported out with the exit conveyor ( 6 ). as shown in fig2 surface mount components ( 2 ), such as qfp ( 2 a ) and chip component ( 2 b ), and insert mount components ( 3 ), such as aluminum electrolytic capacitor ( 3 a ) and switch component ( 3 b ), are placed together on the printed circuit board ( 1 ). this printed circuit board ( 1 ) is transported in the reflow device in a position such that the body sections of the insert mount components ( 3 ) are located on the lower side of the printed circuit board ( 1 ). as means for transporting , conveyors ( 7 ) and ( 8 ) pass through the preheating section ( 4 ) and the main heating section ( 5 ) respectively . the conveyor ( 7 ) transports the printed circuit board ( 1 ) at a prescribed speed through the preheating section ( 4 ). the conveyor ( 8 ) transports the printed circuit board ( 1 ) at a quick speed to and from a prescribed position in the main heating section ( 5 ). means for pushing boards ( 9 ), to push the printed circuit board ( 1 ) which has reached the terminus of the conveyor ( 7 ) onto the conveyor ( 8 ), is placed between the conveyors ( 7 ) and ( 8 ). a board stopper ( 10 ), as a board stopping mechanism to stop the printed circuit board ( 1 ) at a prescribed position , is placed near the board transport surface of the main heating section ( 5 ). placed below the board transport surface of the main heating section ( 5 ) are a cooling device ( 12 ), which supports the printed circuit board ( 1 ) while blowing cool air onto and cooling prescribed locations thereon ; a ventilation fan ( 13 ) to ventilate this cooling device ( 12 ); and a raising and lowering cylinder ( 11 ), as means to lift and lower boards , for lifting and lowering the cooling device ( 12 ) and carrying the printed circuit board ( 1 ) to a prescribed heating position . cooling fans ( 14 ) and ( 15 ), to move air above and below and cool the printed circuit board ( 1 ), are located at the terminus of the conveyor ( 8 ) on the downstream side of the main heating section ( 5 ). also , exhaust ducts ( 16 ) are located between and at either end of the preheating section ( 4 ) and the main heating section ( 5 ). as shown in fig3 the preheating section ( 4 ) is constituted of a hot air heater ( 17 ), to produce hot air ; a hot air recirculation fan ( 18 ), to send the hot air from one side and along the upper surface of the printed circuit board ( 1 ); a catalyst ( 19 ) located on the hot air recirculation path and which burns off fumes of the flux and solvents produced from the solder cream , for example , during the heating of the printed circuit board ( 1 ); a panel heater ( 20 ), located in the upper section of the board transport path of the conveyor ( 7 ), for radiant heating of the upper surface of the printed circuit board ( 1 ); and an atmosphere exhaust duct ( 21 ), located in the lower section of the transport path . as shown in fig4 the main heating section ( 5 ) has a panel heater ( 22 ), as means of radiant heating for the surface of the printed circuit board ( 1 ), and means for hot air heating ( 23 ), for blowing hot air locally and roughly perpendicular to the points to be connected on the surface of this printed circuit board ( 1 ). means for hot air heating ( 23 ) is equipped with hot air header ( 25 ), forming a flat space ( 24 ) and touching the lower surface of the panel heater ( 22 ); a mask plate ( 26 ), placed on a surface of this hot air header ( 25 ) opposite the printed circuit board ( 1 ), wherein blow holes ( 27 ), corresponding to the points to be connected are formed , and on which a black body paint coating is made ; and a hot air supply duct ( 28 ), to supply hot air within the hot air header from one side thereof . within the hot air header ( 25 ), a dispersion plate ( 30 ), on which a plurality of through air holes ( 29 ) is dispersed , is placed with space between itself and the mask plate ( 26 ). hot air is supplied from the hot air supply duct ( 28 ) to between the dispersion plate ( 30 ) and the panel heater ( 22 ). hot air sources such as the hot air heater ( 35 ) and the hot air ventilation fan ( 36 ) pass through the hot air supply duct ( 28 ) as shown in fig5 . meanwhile , as shown in fig4 a hot air nozzle tube ( 31 ), to blow hot air uniformly from its entire length , is placed inside the hot air supply duct ( 28 ). moreover , in the example shown in fig4 the hot air supply duct ( 28 ) is placed on one side of the hot air header ( 25 ), but the present invention is not limited to that . for example , as shown in fig6 the constitution may also be such that a hot air supply duct ( 33 ) is placed so as to surround the periphery of the hot air header ( 25 ) and a rectangular , annular hot air nozzle tube ( 34 ) is placed therein to send hot air from the hot air source to the right place . such a structure can form a more uniform hot air and permit hot air heating with good precision . a section with small holes ( 37 ) for local cooling , in which small holes to blow cool air are installed , and a board support element ( 38 ), to support the printed circuit board ( 1 ), are placed in the cooling device ( 12 ). as shown in fig7 ( a ) and ( b ), the section with small holes ( 37 ) may be constituted with a flat plate ( 40 ) in which holes ( 39 ) are made , or may have a structure with nozzles ( 41 ), conforming to the height of the printed circuit board ( 1 ), mounted on a plate ( 42 ) for blowing cool air from holes ( 39 ) in the nozzles ( 41 ), as shown in fig7 ( c ) and ( d ). here , the distance from the nozzles ( 41 ) to the cooled sections of the printed circuit board ( 1 ) may be adjusted . also , blow holes may be made in a metal or resin block and the cool air blowing distance , corresponding to the height of the insert mount components ( 3 ), may also be adjusted by the carving of the block . as shown in fig8 a fan ( 45 ), to ventilate the lower surface of the board with some of the air stream by the wind direction plate ( 44 ), may also be installed in the cooling section where the cooling device ( 12 ) is installed . as shown by the solid line in fig4 an isolation plate ( 32 ) is installed at a position where it surrounds the periphery of that printed circuit board ( 1 ) when the raising and lowering cylinder ( 11 ) has raised the printed circuit board ( 1 ) to a prescribed heating position . this isolation plate ( 32 ) prevents the intermixing of the heating atmosphere for the upper section of the printed circuit board ( 1 ) and the cooling atmosphere from the cool air , as shown by the broken arrow ( c ) from means for cooling ( 12 ) in the lower section . as shown in fig9 means for pushing boards ( 9 ) is constituted of a chain ( 46 ), a driving motor ( 47 ), and a lever ( 48 ) affixed to the chain ( 46 ). the operation of the reflow device , constituted as noted above , is explained . the conveyor ( 7 ) transports the printed circuit board ( 1 ), on which surface mount components ( 2 ) and insert mount components ( 3 ) are present together , at a certain speed into the preheating section ( 4 ). inside the preheating section ( 4 ), the entire upper surface of the printed circuit board ( 1 ) is heated to a temperature in the vicinity of 150 ° c . with the radiant heat from the panel heater ( 20 ) and the side flow hot air stream . the load on the hot air heater ( 17 ) is reduced because the hot air of a certain temperature is recirculated , while regularizing the temperature of the atmosphere within the preheating section ( 4 ). the temperature of the body sections of the insert mount components ( 3 ), which are transported in a position on the lower surface of the printed circuit board ( 1 ), is increased by the conduction of heat from the lead sections on the upper surface of the printed circuit board ( 1 ). with the constitution in which the atmosphere exhaust duct ( 21 ) continually takes in the atmosphere of the lower surface of the printed circuit board ( 1 ), room temperature atmosphere is guided to the lower surface of the printed circuit board ( 1 ), draws heat from the body sections of the insert mounted components ( 3 ), and suppresses temperature increases of the body sections . having completed preheating , the printed circuit board ( 1 ) reaches the terminus of the conveyor ( 7 ) where means for pushing boards ( 9 ) pushes the rear end of the printed circuit board ( 1 ) and smoothly transfers the printed circuit board ( 1 ) to the conveyor ( 8 ). means for pushing boards ( 9 ) is established in this way because it is necessary to transport the printed circuit board rapidly ; the conveyor ( 7 ) is moved at a speed of 0 . 8 m / min , for example , because the printed circuit board ( 1 ) is heated while it is transported continuously through the preheating section ( 4 ), through which the conveyor ( 7 ) runs , but the printed circuit board ( 1 ) is stopped at a prescribed position with the board stopper ( 10 ), raised to a prescribed heating position by the raising and lowering cylinder ( 11 ), and is heated in the main heating section ( 5 ), in which a separate conveyor ( 8 ) is operating . the printed circuit board ( 1 ), transported into the main heating section ( 5 ), is stopped at a prescribed position with the board stopper ( 10 ) and the conveyor ( 8 ) is also stopped . then means for cooling ( 12 ) is raised by the raising and lowering cylinder ( 11 ) and the printed circuit board ( 1 ), which is supported on the upper end thereof , is raised to a prescribed heating position surrounded by the isolation plate ( 32 ). in this state , the upper surface of the printed circuit board ( 1 ) is heated through the heat header ( 25 ) with the radiant heat from the panel heater ( 22 ). at the same time , hot air is blown from the blow holes ( 27 ) of the mask plate ( 26 ), in means for hot air heating ( 23 ), locally and roughly perpendicular to the points to be connected of the surface mount components ( 2 ) and the lead sections , etc ., of the insert mount components ( 3 ). consequently , the points to be connected only can be heated quickly and with good precision to the prescribed temperature with hot air of a temperature which does not exceed the temperature of heat resistance of the surface mount components . the solder cream of the points to be connected melts and reflow soldering is performed . also , the insert mounted components ( 3 ), positioned on the lower surface of the printed circuit board ( 1 ), are cooled with the section with small holes ( 37 ) for local cooling , in which holes ( 39 ) to blow cool air are installed corresponding to the position of the insert mounted components ( 3 ). with this structure , as shown in fig1 ( a ) and ( b ), the temperature t x of the point to be connected x in the lead of the qfp ( 2 a ), as one example of a surface mount component ( 2 ), and the temperature t y of the point to be connected y in the lead of the aluminum electrolytic capacitor ( 3 a ), as one example of an insert mount component ( 3 ), are 200 ° c . or greater . the solder cream of the points to be connected melts satisfactorily and reflow soldering is performed with certainty . meanwhile , the temperature t z of the body section z of the aluminum electrolytic capacitor ( 3 a ) becomes 160 ° c . or less and heat damage to the aluminum electrolytic capacitor ( 3 a ) can be prevented with certainty . in this way , since the radiant heating and hot air heating act together concurrently , soldering can be performed with certainty even though the temperature of the hot air does not exceed the temperature of heat resistance of the electronic components . meanwhile , hot air is blown locally and roughly perpendicular to the points to be connected and only those points to be connected are selectively heated . while heat damage to sections other than points to be connected is prevented , the solder of the points to be connected can be definitely melted again and result in soldering ; soldering with high reliability is ensured . also , damage to components with low heat resistance , such as the body sections of insert mounted components ( 3 ), among the electronic components can be prevented and batch reflow soldering of electronic components on the printed circuit board ( 1 ) can be performed . also , since the mask plate ( 26 ) is installed between the panel heater ( 22 ) and the printed circuit board ( 1 ), the supply of radiant thermal energy to surface mount components ( 2 ), which are not subject to cooling , can be isolated and the temperature increase can be controlled . the isolation plate ( 32 ) can also prevent the intermixing of the cooling atmosphere and the heating atmosphere of the main heating section ( 5 ). when the prescribed heating operation is complete , the printed circuit board ( 1 ) is lowered to the position of the conveyor ( 8 ) once more and the level of the cooling device ( 12 ) is dropped below that . in effect , the cooling device ( 12 ) is lowered and the heating of the cooling device ( 12 ) itself by the radiant heat is suppressed by its separation of the panel heater ( 22 ). when the cooling device ( 12 ) begins to drop , the cooling of the insert mount components ( 3 ) is insufficient . to compensate for this , the lower surface of the printed circuit board ( 1 ) is ventilated with some air from the fan ( 45 ) by the wind direction plate ( 44 ). moreover , when the printed circuit board ( 1 ) is transported from the main heating section ( 5 ), the wind direction plate ( 44 ) is set horizontally and the cooling device ( 12 ) is cooled with wind from the fan ( 45 ). also , the printed circuit board ( 1 ) is transported from the main heating section ( 5 ) with the conveyor ( 8 ) and is cooled with the cooling fans ( 14 ) and ( 15 ). then the printed circuit board ( 1 ) transfers to the exit conveyor section ( 6 ) from the conveyor ( 8 ) and is transported to the exit of the reflow device .