Patent ID: 8741547

Claim:
A multi charged particle beam writing method comprising: detecting a defective beam in multiple beams having passed through a plurality of openings of an aperture member in which the plurality of openings are formed for forming the multiple beams by irradiation of a charged particle beam; setting a region such that more openings in remaining openings except for an opening through which the defective beam passes in the plurality of openings of the aperture member are included in the region; selecting a mode from a first mode in which a pattern is written on a target object by using multiple beams that have passed openings in the region and a second mode in which multiple writing is performed while shifting a position by using at least one of remaining multiple beams in a state where the defective beam is controlled to be beam off and additional writing is performed for a position which was supposed to be written by the defective beam; and writing a pattern on a target object in the mode selected.