A charged particle beam writing apparatus includes a storage unit to store each pattern data of plural figure patterns arranged in each of plural small regions made by virtually dividing a writing region of a target workpiece to be written on which resist being coated. The charged particle beam writing apparatus further including an assignment unit to assign each pattern data of each figure pattern to be arranged in each of the plural small regions concerned, and a writing unit to write, for each of plural groups, each figure pattern in each of the plural small regions concerned by using a charged particle beam.