A method of manufacturing a semiconductor device includes forming an insulating film on a surface of a semiconductor layer, forming a resist on a surface of the insulating film, the resist having an opening, forming a hardened layer on an inner circumference of the resist by attaching a pattern shrinking agent to the resist, the pattern shrinking agent undergoing a cross-linking reaction with the resist, etching the insulating film using the resist and the hardened layer as masks, removing the hardened layer, and forming a metal layer on a surface of the semiconductor layer, on a surface of the insulating film, and on a surface of the resist. The method further includes removing the resist and the portion of the metal layer on the surface of the resist by lift-off.