The invention relates to an electron accelerator including an evacuated acceleration tube, a target exposed to the electron beam, an electron absorber following the target in beam direction, a collimator and a compensation body arranged therein centered on the axis of symmetry thereof. In such electron accelerators, used in radiotherapy, the soft radiation component is to be suppressed as much as possible. To this end the invention provides a filter plate made of heavy metal beyond the electron absorber, while the compensation body is made of a material of comparatively low atomic number. The filter plate may be inserted between the electron absorber and the compensation body. The target may be provided on the side of the electron absorber facing the acceleration tube.