The basic principles of electron backscattering from atoms and solids in the energy range 10 to 100 keV are reviewed. The total backscattering from thin self‐supporting films, from bulk solids, and from thin surface films on supporting bulk solids is discussed as well as the angular distribution of the backscattered electron intensity for normal and for oblique incidence of the primary beam. The results of theoretical models are compared with experimental results. Contrast mechanisms in scanning electron microscopy based on electron backscattering and the influence of diffraction effects are described. Finally the thickness determination of thin films by electron backscattering and by other methods is reviewed.