ITO thin layers were deposited with good results on a glass substrate by Spray pyrolysis method under optimal conditions using the TAGUCHI experimental design. Structural, optical and electrical characteristics have been studied and evaluated via X-ray diffraction, UV–visible spectrophotometry and the 4-point probe method. On the optical analysis by taking measurements of average transmittance T (λ) and absorption A (λ) over the wavelength interval from 300 to 1000 nm, the indirect band gap energy can be determined. The analysis of our ITO thin films shows that the confirmatory test has the best performance. The ideal preparation conditions of ITO thin films were the following: surface temperature is 450 °C, the ratio of indium and tin was 10%, as well as the deposition time was 10 min. The mean optical transmittance in visual range and sheet resistance of ITO film were 85% and 22.38 Ω/□, respectively.