An electron beam irradiation apparatus which exposes a wafer coated with an electron beam resist with an electron beam is equipped with: a stage that can be moved holding the wafer; an electron beam optical system that irradiates the wafer with an electron beam; and, an opening member, placed facing the wafer via a predetermined gap on the wafer side in the optical arrangement direction of the electron beam optical system, and having an opening through which the electron beam from the electron beam optical system passes.