The present invention relates to method and apparatus for correcting defects of an X-ray mask comprising the steps of: irradiating a focused ion beam to at least a region having a defective portion of an X-ray mask (200) having a protective film (204, 304) and eliminating the protective film; exposing a circuit pattern (205, 305) having a defective portion (150, 160) locating under the region or setting this circuit pattern to the state near the exposure; detecting at least one of the secondary electrons, secondary ions, reflected electrons, and absorbing current generated from that region and detecting a true defective position; positioning the focused ion beam to the true defective position and irradiating the focused ion beam to the defective portion; and thereby correcting the defect.