PURPOSE: To reduce the defect of a capacitor in a semiconductor device wherein at least one electrode for the capacitor is constituted of an aluminum electrode.

CONSTITUTION: A field insulating layer 12, an interlayer insulating layer 13, an insulating layer 14 for capacitor use, an electrode 15, for lower-side capacitor use, which uses a high-melting-point metal, an aluminum electrode 16 to be used as an electrode for upper-side capacitor use and a conductive protective layer 17 using a high-melting-point metal are formed respectively on the main face side of a silicon substrate 11. Since the protective layer 17 is formed between the insulating layer 14 for capacitor use and the aluminum electrode 16, it is possible to restrain a hillock from being formed during a heat treatment and to enhance the dielectric breakdown strength of a capacitor.