one example of a reactive ionized cluster beam deposition method and an apparatus thereof according to this invention will hereinafter be described in greater detail with reference to the drawings . fig1 schematically illustrates a reactive ionized cluster beam deposition apparatus 1 in one example according to the present invention . this deposition apparatus 1 takes a double chamber structure wherein a vacuum region is partitioned by a partition wall 2 into a first vacuum subregion 3 formed downward and a second vacuum subregion 4 formed upward . a closed type heating crucible 5 for heat - vaporizing an evaporative substance is installed in the first vacuum subregion 3 . the closed heating crucible 5 is sectioned into two units , i . e ., an evaporative material supplying unit 5a and a vaporizing unit 5b . the crucible 5 effects resistance - heating which involves the use of materials such as tantalum , tungsten or graphite . the evaporative material supplying unit 5a , which further employs an electron gun jointly as a heating source , controls an evaporation supply quantity of the evaporative material . the vaporizing unit 5b is equipped with multiple injection nozzles 6 arranged in one line . an electron emitter 7 is provided above these injection nozzles 6 . an accelerating electrode 8 is further provided above the electron emitter 7 . the partition wall 2 is also formed with an opening 9 through which clusters pass . a film transfer unit 10 for a plastic film serving as a substrate is provided in the second vacuum subregion 4 upwardly of the partition wall 2 . this plastic film transfer unit 10 includes two rolls 11 and 12 . the roll 11 is a feed roll wound with a plastic film 13 defined as the substrate . the roll 12 is a take - up roll for taking up the plastic film 13 fed out of the feed roll 11 . a positioning roll 14 for positioning the plastic film 13 at a deposition unit above the opening 9 is installed upwardly of the opening 9 formed in the partition wall 2 . the plastic film 13 fed out of the feed rolls 11 is wound on the take - up roll 12 through the positioning roll 14 . a reactive gas introducing pipe 15 is led in the second vacuum subregion 4 . an outlet of this introducing pipe 15 is located between the opening 9 of the partition wall 2 and the positioning roll 14 defined as the deposition unit . the first vacuum subregion 3 is kept under a degree of vacuum ( p ) on the order of × 10 - 4 ˜ 10 - 7 torr . the second vacuum subregion 4 is also kept under a degree of vacuum on the order of × 10 - 2 ˜ 10 - 4 torr with an introduction of the reactive gas . the degree of vacuum in the second vacuum subregion 4 is thus set smaller than in the first vacuum subregion 3 . namely , the second vacuum subregion 4 is set at a higher pressure than the first vacuum subregion 3 . this tends to enhance the gas concentration within the second vacuum subregion 4 into which the reactive gas is introduced so as to induce complete reaction of the deposition substance with the reactive gas in a short length within this vacuum subregion 4 . according to the thus constructed reactive ionized cluster beam deposition apparatus 1 , the deposition substance is heated in the closed heating crucible 5 so that the vapor pressure ( p 0 ) thereof becomes 1 ˜ 10 torr . at this time , it is required that a relationship between the vapor pressure in the closed heating crucible and the pressure of the first vacuum subregion 3 in the outside thereof be selected to satisfy this relationship : p 0 / p & gt ; about 10 4 ˜ 10 5 . then , a vapor of the deposition substance is injected from each injection nozzle 6 of the closed heating crucible 5 into the first vacuum subregion 3 having a degree of vacuum on the order of × 10 - 4 ˜ 10 - 5 torr . the vapors injected from the injection nozzles 6 form atom clusters with an adiabatic expansion . the atom clusters are ionized by the electron emitter 7 and thereafter accelerated by the accelerating electrode 8 . the ionized clusters produce ionized cluster beams 16 therein . the ionized cluster beams 16 pass through the opening 9 of the partition wall 2 and enter the second vacuum subregion 4 . the cluster beams react with the reactive gas therein and bombard the surface of the plastic film 13 passing above the opening 9 with the aid of the positioning roll 14 . with this bombardment , the respective atoms of the ionized clusters are scattered . there appears the same effect as causing biaxial orientation of a plastic film . a hyperfine structure thereof can be remarkably improved . by the way , the following question arises with respect to the reactive ionized cluster beam deposition apparatus 1 having the above - mentioned construction . even if the vacuum region is partitioned by the partition walls 2 into as many subregions as possible , the opening 9 serving as a beam passageway is formed in the partition wall 2 . consequently , the reactive gas easily flows into the first vacuum subregion 4 exhibiting a higher degree of vacuum . it seems that the respective degrees of vacuums in the two vacuum subregions 3 , 4 can not be maintained . concerning this point , however , there is no problem if the pressure of the cluster beams 16 in the opening 9 of the partition wall 2 is equal to or greater than the pressure of the reactive gas which is to enter the first vacuum subregion . this point will be explained in greater detail . a total beam energy immediately after the injection is , it can be judged , substantially equal to a total beam energy in the opening 9 . it therefore follows that a pressure of the cluster beam 16 per unit area in the opening 9 of the partition wall 2 is in reverse proportion to a ratio of the an injection nozzle area to a beam diffused area in the opening 9 . now , a diameter of each injection nozzle 6 in the closed heating crucible 5 is set to 2 mm . a vapor pressure of the deposition substance is set at 1 ˜ 10 torr , and an injection angle of set at ± 10 degrees . in this case , the beam diffused area apart 20 cm from the injection nozzle is approximately 1000 times as large as the injection nozzle area . it is sufficiently possible to keep the pressure per unit area in the injecting direction on the order of 10 - 3 torr . besides , a kinetic energy given by an ionization accelerating voltage is added thereto , and hence there is absolutely no problem . as obvious from this , the reactive gas does not flow into the first vacuum subregion 3 via the opening 9 from the second vacuum subregion 4 . accordingly , the closed heating crucible 5 and the accelerating electrode 8 are not degraded . if the distance from the injection nozzle 6 to the opening 9 thus increases , however , the injection pressure of the beam 15 abruptly decreases enough to reduce the effect of preventing the reactive gas from entering the first vacuum subregion 3 . it is therefore necessary to pay considerable attention to a location of the partition wall 2 . next , an embodiment of the reactive ionized cluster beam deposition method of this invention will be explained . silicon monoxide ( sio ) serving as a deposition substance is put into the tantalum heater crucible 5 disposed at the lowermost portion of the first vacuum subregion 3 in the apparatus illustrated in fig1 . a temperature is kept at 1600 ˜ 1700 k ( see fig2 in the form of a graphic chart showing a relationship of temperature versus vapor pressure ) in the injection unit so that a vapor pressure of sio becomes 1 ˜ 10 torr . the evaporative material supplying unit 5a of the closed heating crucible 5 continuously supplies the sio vapor corresponding to an injection quantity by electron beam heating . the vaporizing unit 5b of the closed heating crucible 5 is formed with seven injection nozzles 6 each having an aperture diameter of 2 mm and arranged at intervals of 3 cm in the horizontal direction . each injection nozzle 6 injects the sio vapor toward the first vacuum subregion 3 in which the degree of vacuum is kept at 5 × 10 - 4 ˜ 10 - 5 torr . atom clusters of the sio vapor injected from each injection nozzle 6 are , as illustrated in fig1 ionized by the electron emitter 7 ( ionization voltage : 0 . 5 kv , ionization current : 200 ma ) immediately after the injection . just when a distribution of sio vapor concentrations becomes uniform in the horizontal direction , an acceleration energy is given at an acceleration voltage of 5 kv toward the substrate . the ionized atom clusters of the sio vapor are thereby made to pass through the opening 9 ( 18 cm × 7 cm ) of the partition wall 2 installed 20 cm upward from the injection nozzle 6 and introduced into the second vacuum subregion 4 . the second vacuum subregion 4 formed upwardly of the partition wall 2 is supplied with oxygen gas ( o 2 ) as the reactive gas . the exhaust quantity is controlled so that the degree of vacuum falls within a range of 5 × 10 - 3 ˜ 5 × 10 - 4 torr . the gas concentration is set so that a bombardment distance of 10 cm or less required for a sufficient advancement of reaction of the sio vapor with the reactive gas is to be expected . the deposition substrate involves the use of a biaxially orientated polyester film having a thickness of 20μ and a width of 20 cm and run by the plastic film running unit 10 at a speed of 20 m / min . the vaporization continues under the conditions described above till the entire quantity of sio existing in the crucible is consumed up . the degrees of vacuums in the first and second subregions 3 , 4 partitioned by the partition wall can be easily continuously kept within the set range mentioned above . further , stable deposition can be obtained without causing a glow discharge . a deposited film deposited on the deposition substrate polyester biaxially oriented film has such characteristics that the film is colorless and transparent in terms of its appearance , its thickness is approximately 400 å as a mean value when measured at several points , and an ir absorption peak ( see fig3 ) is about 1065 cm - 1 . it is judged that a substantially complete sio 2 film is deposited thereon . note that fig3 shows , for reference , a measurement example of a test for a deposition velocity and an oxidation characteristic when an oxygen gas concentration is 1 × 10 - 4 torr and 2 × 10 - 4 torr . this embodiment is intended for industrial production , and deposition is effected at a speed that is several hundred times that of the test condition shown in fig3 . nevertheless , however , it is judged that complete and stable oxidative reaction is obtained . the result is that the availability of the reactive gas concentration increased this effect owing to the double - compartment separation has been demonstrated . a food packaging film may be given as an application of the plastic film having its surface formed with the deposited film by this reactive ionized cluster beam deposition method . namely , the plastic film formed with the deposited film by the deposition method according to this invention has an extremely good hyperfine structure because of its deposited film exhibiting the same effect as causing the biaxial orientation of the plastic film as explained earlier . this plastic film is therefore excellent in terms of a water vaporproof performance and an oxygen barrier performance as well . incidentally , if a deposited film of indium oxide is formed on the plastic film by the method of this invention , a transparent conductive film exhibiting a good conductivity can be provided at low costs . as discussed above , according to the reactive ionized cluster beam deposition method and apparatus thereof of this invention , the deposited film deposited on the upper surface of the substrate has a really excellent property . as a result , it is possible to provide film formed with the deposited film that is superlative in terms of the water vaporproof performance and the oxygen barrier performance as well . when this film is employed for packaging foods , it also serves remarkably well in preserving them . further , when the deposited film of indium oxide is formed on the plastic film by the deposition method of the present invention , a transparent conductive film exhibiting good conductivity can be provided . the application field of this invention is very broad . according to the present invention , it is feasible to provide a film formed with the deposited film having excellent water vaporproof and oxygen barrier performance . this film can therefore be employed for packaging foods . a transparent conductive film manifesting the good conductivity can be also provided and therefore used as part of a film - like solar cell .