[en] The theoretical model for electron-beam-induced conductivity in thin insulating films is reviewed and its application to gain measurements in several different insulating materials is discussed. The ideas incorporated in the model suggest a technique for investigating trapping levels in insulators, using the electron beam as a means of populating the traps. It is suggested that, in addition to determining the trap energy, it may be possible to investigate the spatial distribution of the traps. Electron-beam-radiation effects in SiO₂ are briefly commented upon and the dependence of Δ Vsub(FB), the shift in flat-band voltage of MOS capacitors, on beam energy is discussed in terms of the gain model. Finally consideration is given to the problem of observing voltage contrast from the passivated devices in a scanning electron microscope. (author)