The aim of the present study is to investigate the influence of the TiO 2 specific surface (powder, film) on the photocatalytic degradation of methyl orange. Porous TiO 2 films were deposited on transparent conducting oxide substrates by spray pyrolysis deposition. The films were characterized by X-ray diffraction (XRD), Scanning Electronic Microscopy, and the UV–Vis spectroscopy. The XRD spectra of nanoporous TiO 2 films revealed an anatase, crystalline structure that is known as the most suitable structure in photocatalysis. The average thickness of the films was 260 nm and the measured band gap is 3.44 eV. The influence of the operational parameters (dye concentration, contact time) on the degradation rate of the dye on TiO 2 was examined. There were calculated the kinetic parameters and the process efficiency. Using thin films of TiO 2 is technologically recommended but raises problems due to lowering the amount of catalyst available for the dye degradation.