The method of manufacturing a semiconductor device selectively forms a resist film on the multilayer gate film and the gate side wall insulating film extending on the semiconductor substrate. An upper part of the gate side wall insulating film and the hard mask film selectively are removed by etching using the resist film as a mask so as to expose a surface of the metal film. the metal film and the barrier metal film adjoining the metal film are removed, by wet etching. After the removal of the resist film, embedding a space formed by removal of the metal film and the barrier metal film and depositing a pre-metal dielectric to a level higher than an upper surface of the remaining hard mask film. A top part of the pre-metal dielectric is planarized by CMP using the remaining hard mask film as a stopper.