The present invention relates to a method and apparatus for correcting defects of an X-ray mask which includes a focused ion beam used to irradiate at least a region having a defective portion of an X-ray mask having a protective film and eliminating the protective film; exposing a circuit pattern having a defective portion located under the region or setting this circuit pattern to the state near the exposure; detecting one of the secondary electrons, secondary ions, reflected electrons, or absorbing current generated from that region and detecting a true defective position. Then positioning the focused ion beam to the true defective position and irradiating the focused ion beam to the defective portion thereby correcting the defect.