A method of producing a compound semiconductor device using a lift-off process. The lift-off process includes forming a resist mask having an electrode opening on an active layer of a compound semiconductor that is on a substrate of a compound semiconductor; forming a metal layer on the resist mask and the active layer in the electrode opening; and dissolving the resist mask and removing the metal layer on the resist mask, leaving the metal layer on the active layer in the electrode opening as an electrode. The resist mask is removed sufficiently by using a resist remover consisting essentially of at least one compound selected from an amine-including compound and nitrogen-including cyclic compounds so that the residual resist mask need not be removed by ashing.