Metal oxides with the forbidden band gap more than 3eV are transparent for the solar radiation and, when doped with respective impurities, get an increased electrical conductivity comparable with that of metals. They have been named TCO and are largely used in photovoltaic devices as active and passive elements. One agent from this group of materials is ITO, the mixture of tin and indium oxides SnO2 and In2O3. In our case ITO is used for the formation of ITO/Si junction and for the development of solar cells on their base. The aim of the present communication is the study of the influence of deposition conditions on the structure and the chemical composition of ITO thin films. ITO thin films have been obtained using two variants of spray deposition. The first variant was described in [1] and is characterised by direct spraying of the diffused flux of the drops of the alcoholic solution of the mixture of indium and tin chlorides on the surface of single crystalline Si wafers. This surface can be smooth or texturized. The second variant of the deposition process, named indirect spraying, differs from the first one. In the second case, the flux of solution drops does not directly hit the silicon surface, but, first, passes through a glass tube supplied with a labyrinth of obstacles, which favours a more intense dispersion of the solution drops. Hence, rather a flux of solution vapours is formed on the substrate surface but not a flux of dispersed drops. In addition, the speed of the vapour flux can be controlled in a wide range of values. The analyses of the morphology and of the chemical composition of ITO layers have been carried out by SEM microscopy using a Gemini LEO 1530 microscope and the INCA Energy EDX system of chemical composition determination. ITO thin films with the thickness 280-300nm were obtained on the smooth surface of Si single crystals by direct spraying at the compressed air pressure of 0.5atm, using 12ml of the solution, whereas at indirect spraying, for the same quantity of solution and air pressure of 0.1atm, the ITO thin films thickness is 660-700nm. In both cases the layer consists of crystallites in the form of parallelepipeds with tetrahedral pyramids in peaks. Crystallites grow perpendicularly to (100) oriented silicon surface. If texturized Si substrates are used (inverted pyramids obtained by photolithography) ITO layer deposited by direct spraying evenly covers the surface. Indirect spraying provides full coverage by ITO of the texturized silicon surface, but the coverage is uneven - thicker outside of pyramids and thinner within them. The crystallite parameters, when ITO layers are obtained by indirect spraying of ethyl chloride solution of indium and tin are ~ 200x200x500nm, while when using direct spraying of the solution they are ~ 100x100x200nm. The perimeter of the pyramid inverted base at ITO coating of the Si surface decreases more significantly by indirect than by direct spraying. The analyses of EDX spectra demonstrate that the chemical composition of the thin ITO layers deposited on the silicon wafers surface is close to the stoichiometrical composition. ITO thin layers obtained by spray technique on the (100) surface of silicon wafer, are polycrystalline. Tetrahedrally shaped crystallites grow perpendicular to the substrate plane, their height is comparable to the thickness of the layer, and the side width reaches values ~ 200x200nm for indirect spraying by the chemical solution of indium and tin chlorides. On the base such of ITO layers deposited on the texturized surface of Si wafers, formed by inverted pyramids, ITO/Si structures and Ag/n+ITO/SiO2/nSi/n+Si/Ag solar cells have been obtained with the record efficiencies of 15% for this type of devices. [1] Simashkevich, A.; Serban, D.; Bruc, L.; Coval, A.; Fedorov, V.; Bobeico, E. & Usatii. Iu. (2005). Proc. of the 20th European Photovoltaic Solar Energy Conference, pp.980-982.