The radiation resistance of SnO 2 -Si sensor structures irradiated by fast electrons and γ rays was studied. The radiation-induced structural changes were investigated using the Fourier transform infrared (FTIR) spectroscopy method. FTIR spectroscopy was used with grazing angles of light incidence on the surface of SnO 2 -Si structure. New bands or any other modifications in spectra for irradiated SnO 2 films were not observed. It was found that SnO 2 films reveal a high resistance to irradiation while structural changes were observed in the silicon substrate.