In an article, studies of tin dioxide films for challenging sensitive elements of gas sensors for monitoring gaseous impurities in air have been described. The technological influence issues parameters of the process producing of tin dioxide films by magnetron sputtering at a fixed magnetron power on their crystal structure and phase composition were considered. The substrate temperature, layer thickness, and oxygen concentration in the atomized gas were considered as parameters. The foundation for improving the constructive and technological solutions of film gas sensors based on the research results was laid.