An electron beam irradiation apparatus (2) is provided that includes a vacuum room (40), an electron beam generator (34), a window frame (48) or a window (44), and an irradiation foil (52). The vacuum room includes a wall having an opening through which an electron beam is irradiated. An internal atmosphere of the vacuum room is evacuated. The electron beam generator is provided inside the vacuum room. The window frame is attached to and surrounds the opening in the wall of the vacuum room. The irradiation foil, through which an electron beam generated in the vacuum room is transmitted, is fixed to the window frame. The surface of the window frame, at least an area exposed to the vacuum room, is substantially covered with material (56) including an element or elements with an atomic number less than or equal to 10.
