An object of the present invention is to provide an electron beam
apparatus, in which a plurality of electron beams, e.g., four electron
beams, is produced for one optical axis with a relatively high current
achieved for each electron beam.Provided is an electron beam apparatus
comprising: an electron beam emitter (32) having an electron gun (30),
said electron gun (30) disposed along an optical axis (23) and operable
to emit a plurality of off-axis electron beams along a direction defined
by a certain angle with respect to the optical axis (23); a plurality of
apertures (34) disposed at a location offset from the optical axis (23);
and an electromagnetic lens (7) for forming a magnetic field between the
electron gun (30) and the apertures (34) to control the plurality of
off-axis electron beams emitted from the electron gun (30) so that the
plurality of off-axis electron beams passes through the apertures (34).