The charged particle beam drawing apparatus of the present invention performs drawing to a substrate with a plurality of charged particle beams. The drawing apparatus includes an electron lens positioned at a location facing opposite to the substrate and including a plurality of holes through which the charged particle beams pass; and a cleaning unit configured to release active species to a decomposition product that has adhered to the electron lens and reduce the decomposition product by the reaction of the active species and the decomposition product to thereby change the decomposition product to a volatile gas. Here, the cleaning unit has a plurality of openings formed such that the active species are released toward the plurality of holes of the electron lens.