To prevent oxidation of a barrier substance in an oxidation atmosphere by forming a gate electrode on a semiconductor substrate via a gate insulating film, and constituting the electrode by sequentially laminating a polysilicon, a metal silicon nitride film and a metal silicide in this order.

A gate insulating film 22 is formed on a semiconductor substrate 21, and a polysilicon 23 is formed on the film 22. Then, a metal silicon nitride film 24 made of titanium-silicon-nitrogen components is formed, and a titanium silicide 25 is formed on the film 24. Subsequently, a hard mask substance film 26 is deposited on the titanium silicide 25, and the film 26 is removed so as to retain it only on the gate region. The titanium silicide 25, the metal silicon nitride film 24 and the polysilicon 23 are selectively removed by using the layer 26, and a gate electrode 27 is formed.