In a method for repairing phase shifter defective portion 6 according to this embodiment, a light shielding film 14 made of a material such as chromium, carbon, molybdenum silicide, tungsten silicide, molybdenum, tantalum, tungsten, silicon or the like is formed at phase shifter defective portion 6 and at a region protruding by a predetermined length (Hi) from a normal boundary between light trans