Energy beam irradiation device

An energy beam emission device comprising:

• an electron discharge unit having a long electron discharge part;
• a housing having a window from which energy beams are emitted on the basis of electrons discharged from the electron discharge part;
• and
• a unit accommodation part fixed in the housing, having a long tubular shape capable of accommodating the electron discharge unit, and having an electron discharge opening formed in a portion of an outer peripheral surface facing the window,
• wherein a plurality of positioning parts are provided between an outer surface of the electron discharge unit and an inner surface of the unit accommodation part, the positioning parts being slidably in contact with an outer surface of the electron discharge unit or an inner surface of the unit accommodation part and performing positioning of the electron discharge part with respect to the unit accommodation part, and
• wherein the electron discharge unit is capable of being inserted into the unit accommodation part from an end of the unit accommodation part.