After formation of a contact pattern on a semiconductor substrate, a first wiring pattern composed of a first barrier metal film and a first conductor pattern is formed on the contact pattern. A moisture-proof ring is formed which has such a structure that an outer peripheral portion, covering a sidewall face on the outer peripheral side of the first conductor pattern, of the first barrier metal film, is in contact at the upper end portion with a barrier metal bottom face portion, covering the bottom face of a via contact portion, of a second barrier metal film. This results in formation of a barrier metal film such as Ta, TiN, or the like, with no discontinuation, in the whole region from the semiconductor substrate to an silicon oxide film being the uppermost layer, thereby improving adhesiveness for prevention of cracks and entry of moisture.