A solid electrolytic capacitor comprises a capacitor element which is composed of an anode foil (4) and a cathode foil (5) wound with a separator (6) interposed therebetween and has a solid electrolyte layer or a conductive polymer layer formed inside. A dielectric oxide coating film is formed on the anode foil (4). Specifically, a coating film composed of a nitride of a single metal or a composite metal compound is formed on the anode foil (4), and the dielectric oxide coating film is composed of an oxide of this nitride. The nitride of a single metal is any one of titanium nitride, zirconiumnitride, tantalum nitride and niobium nitride. The nitride of a composite metal compound is any one of aluminum titanium nitride, chromium titanium nitride, zirconium titanium nitride, and titanium carbonitride.