Charged particle beam writing apparatus includes a first generation unit to generate a smallest deflection region layer in three or more deflection region layers each having deflection regions of a size different from those of other deflection region layers, for each of a plurality of figure types variably shapable using first and second shaping apertures, an assignment unit to assign each of a plurality of shot figure patterns to deflection regions of the smallest deflection region layer of a corresponding one of the plurality of figure types, a correction unit to correct, by shifting the position of each smallest deflection region layer, according to a variable shaping position of each figure type, and a writing unit to write each of the plurality of shot figure patterns on a target object, in a state where the position of each smallest deflection region layer has been corrected for each figure type.