In a gas-filled space, a pulsed electron beam device comprises a cathode provided with through holes, a filament on one side of the cathode, and an anode on the other side with a sample to be processed held thereon. Electrons emitted by the filament are momentarily directed to the cathode so that a portion thereof may trigger a discharge in a space between the anode and cathode. The discharge ceases in a moment, meanwhile providing electron beams to uniformly process the sample. The cathode may comprise either a single plate of graphite or a combination of a graphite plate and an aluminum plate. Preferably, a net electrode is placed between the cathode and the anode and electrically connected to the anode.