An insulating portion of the respective wiring layers for a semiconductor device is constituted of insulating films. The one insulating film is made of a material whose conductivity is higher than that of the other insulating film that is made of an ordinary silicon oxide film and is provided in contact with the wiring. An electric charge accumulated in the wiring generated in the course of manufacture of the semiconductor device is discharged through the one insulating film at a stage where a charge accumulation in the wiring is low. This permits the heat release value generated through the discharge to be suppressed to a low level, and the short-circuiting-failure between adjacent wirings to be suppressed or prevented.