Tin-doped indium oxide (ITO) thin films were prepared using conventional radio frequency (RF) planar magnetron sputtering equipped with IR irradiation using a ceramic target of In_2O_3/SnO_2 with a mass ratio of 1∶1 at various IR irradiation temperatures T_1 (from room temperature to 400?℃). The refractive index,deposited ratio,and resistivity are functions of the sputtering Ar gas pressure. The microstructure of ITO thin films is related to IR T_1,the crystalline seeds appear at T_1=300?℃,and the films are amorphous at the temperature ranging from 27?℃ to 400?℃. AFM investigation shows that the roughness value of peak-valley of ITO thin film (R_ p-v ) and the surface microstructure of ITO thin films have a close relation with T_1. The IR irradiation results in a widening value of band-gap energy due to Burstein-Moss effect and the maximum visible transmittance shifts toward a shorter wavelength along with a decrease in the film’s refractive index. The plasma wavelength and the refractive index of ITO thin films are relative to the T_1. XPS investigation shows that the photoelectrolytic properties can be deteriorated by the sub-oxides. The deterioration can be decreased by increasing the oxygen flow rate (fo_2),and the mole ratio of Sn/In in the samples reduces with an increase in fo_2. Tin-doped indium oxide (ITO) thin films were prepared using conventional radio frequency (RF) planar magnetron sputtering equipped with IR irradiation using a ceramic target of In 2 O 3 / SnO 2 with a mass ratio of 1: 1 at various types of IR irradiation temperatures T 1 (from The microstructure of ITO thin films is related to IR T_1, the crystalline seeds appear at T_1 = 300 ° C, and the resistivity are functions of the sputtering Ar gas pressure. the films are amorphous at the temperature ranging from 27 ° C. to 400 ° C. AFM investigation shows that the roughness value of peak-valley of ITO thin film (R_pv) and the surface microstructure of ITO thin films have a close relationship with T_1 . The IR irradiation results in a widening value of band-gap energy due to Burstein-Moss effect and the maximum visible transmittance shifts toward a shorter wavelength along with a decrease in the film’s refractive index. The plasma wavelength and t XPS investigation shows that the photoelectrolytic properties can be deteriorated by the sub-oxides. The deterioration can be decreased by increasing the oxygen flow rate (fo_2), and the mole ratio of Sn / In in the samples reduces with an increase in fo_2.