A charged particle beam drawing apparatus has a drawing chamber including a movable stage which supports a mask, the mask being formed by applying a resist to an upper surface of a mask substrate, an optical column for applying a charged particle beam to draw patterns in the resist, a charged particle beam dose correction portion for correcting a dose of the charged particle beam applied from the optical column to the resist on the basis of proximity effect and fogging effect, and a conversion coefficient changing portion for changing a conversion coefficient on the basis of pattern density in the resist and a position in the resist, wherein the conversion coefficient is a ratio of an accumulation energy of the charged particle beam accumulated in the resist, to an accumulation dose of the charged particle beam accumulated in the resist.