An inspection apparatus for inspecting an inspection target object, includes an X-ray generation tube having a target including an X ray generation portion that generates X-rays by irradiation with an electron beam, and configured to emit X-rays to an inspection target surface of the inspection target object, an X-ray detector configured to detect X-rays emitted from a foreign substance existing on the inspection target surface irradiated with the X-rays from the X ray generation portion and totally reflected by the inspection target surface, and an adjustment mechanism configured to adjust a relative position between the inspection target surface and the X-ray detector.