An electron beam sterilizing device comprises an electron-generating filament, a grid connected to a voltage source, a beam shaper, and an output window. A high voltage source generates a high voltage potential between the electron-generating filament and the output window, for acceleration of electrons. The usability of the device is enhanced in that the electron-generating filament and/or the grid electrode comprises at least two operational portions for variation of the current and form of an output electron beam.