The ITO film was deposited onto the polyethylene terephthalate (PET) substrate at room temperature by the inclination opposite target type DC magnetron sputtering equipment. An indium tin alloy (In2O3 (90wt%)+SnO2 (10wt.%)) target was used. The total sputtering pressure and the work voltage were varied from 0.18 to 0.8Pa and from -10 to -90V, respectively. The effects of total sputtering pressure and work voltage on the optical and electric properties of ITO film were discussed. The experimental results obtained were summarized as follows: (1) The ITO film produced at room temperature had microstructure in which a X ray diffraction peak is not clear, regardless of the total sputtering pressure and the work voltage. (2) For PET film deposited ITO film, an optical transmittance was over about 70% at the wave length of 600nm. (3) The absorption edge shifted to short the wave length with decreasing the total sputtering pressure and with increasing the work voltage. (4) For the deposited ITO film, the lowest electrical resistivity was about 6.10×10-4Ω·cm at the sputtering pressure of 0.51Pa when the sputtering pressure increased from 0.18Pa under a constant of -70V.