In an X-ray generator using an ultraviolet laser, the generation of the X-ray is stabilized. In an X-ray generation method for irradiating an ultraviolet laser beam emitted from an ultraviolet laser beam generator on an ultraviolet laser beam receiving surface of an electron beam emitting device, irradiating an electron beam emitted from an electron beam emitting surface of the electron beam emitting device distinguished from the ultraviolet laser beam receiving surface on a metal piece and generating an X-ray from the metal piece, denaturalization of substance of the ultraviolet laser beam receiving surface is prevented by controlling the ultraviolet laser beam.