A wiring film having excellent adhesion and barrier property and a low resistance value is formed. An oxygen gas is introduced into a vacuum chamber in which an object to be film formed is disposed; a sputtering target is sputtered in a vacuum ambience containing oxygen; and a first metallic film is formed on a surface of the object to be film formed. The first sputtering target includes copper as a major component and at least one kind of additive elements selected from an additive element group consisting of Mg, Al, Si, Be, Ca, Sr, Ba, Ra, Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb and Dy. Thereafter, a second metallic film is formed on a surface of the first metallic film by sputtering the sputtering target in a state in which the introduction of the oxygen gas into a vacuum ambience is stopped, and then a wiring film is formed by etching the first and second metallic films.