An electron beam sterilization unit (1) for processing food packaging material, the unit having a frame (2); at least one electron beam emitter (3) fitted to the frame (2), along the path of the material for processing, and having a flange (18) for connection to the frame (2); and a locking device (24), which is fitted to the frame (2), and has thrust devices (45) for exerting a lock force on the flange (18) in a given first direction (34), and for locking the emitter (3), with respect to the frame (2), in a given work position, and actuating devices (46) for activating the thrust devices (45) and which are defined by toggle devices (46).