In this study, we reported the impact of spray time and substrate temperature on several properties of TiO 2 thin layers elaborated by facile and robust spray pyrolysis (SP) technique. The TiO 2 thin layers were characterized by the following techniques: X-ray diffraction (XRD), Raman spectroscopy (RS), scanning electron microscopy (SEM) and UV–visible spectrophotometer (UV–Vis). The XRD results demonstrated the pure anatase phase of TiO 2 thin layers with the preferential direction along < 101 > direction. The vibration characteristics of TiO 2 have been confirmed by Raman vibratory modes located at 143, 396, 518 and 637 cm −1 which certified the formation of a single phase of TiO 2 Anatase. The SEM images showed the formation of granular TiO 2 layers. The UV–Vis spectrophotometer displayed the semiconducting properties of TiO 2 semiconductor, the band gap energy was ranged between 3.10 and 3.30 eV. All parameters investigated in this study confirmed that TiO 2 deposited by the inexpensive spray pyrolysis during 25 min at 500 °C had the required properties for gas sensing applications and are in good agreement with those reported in the literature. The sensing properties of the elaborated TiO 2 thin films to NO 2 showed their high suitability to detect this pollutant gas.