A charged-particle beam writing apparatus includes a writing chamber to house a stage having a writing object placed thereon, a beam irradiator to irradiate a charged particle beam to the writing object placed on the stage, a stage driver to move the stage, a temperature distribution calculator to calculate temperature distribution of the writing object caused by a heat source in the writing chamber, based on movement history information of the stage, a deformed amount calculator to calculate a deformed amount of the writing object based on a constraint condition of the writing object placed on the stage and the calculated temperature distribution, and a position corrector to correct an irradiation position of the charged particle beam to the writing object based on the calculated deformed amount. The beam irradiator irradiates the charged particle beam based on the irradiation position corrected by the position corrector.