A method for manufacturing a compound semiconductor device forms an EB resist layer on first SiN film, performs EB exposure at high dose for recess forming opening and at low dose for eaves removing opening, develops the high dose EB resist pattern to etch the first SiN film, selectively etches the cap layer to form a recess wider than the opening of the first SiN film leaving eaves of SiN, develops the low dose EB resist pattern to form the eaves removing opening, etches the first SiN film to extinguish the eaves, forms second SiN film on the exposed surface, forms a resist pattern having a gate electrode opening on the second SiN film to etch the second SiN film, forms a metal layer to form a gate electrode by lift-off. The SiN film in eaves shape will not be left.