Provided is an X-ray generator for generating X-rays from an X-ray focal point that is a region in which electrons emitted from a filament impinge upon a rotating anode. The X-ray generator has a Wehnelt electrode for surrounding the filament, an attachment part formed integrally with the Wehnelt electrode, a pedestal to which the attachment part is attached, and a casing for housing the pedestal and the anticathode. The width of the space in which the anticathode is housed by the casing is less than the width of the space in which the pedestal is housed by the casing. The Wehnelt electrode extends into the space in which the anticathode is housed by the casing, in a state in which the attachment part is attached to the pedestal.