An inspection apparatus for inspecting an inspection target surface arranged on an inspection plane, 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 the inspection plane, and 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. The X-ray detector includes a long X-ray receiver.