To provide cathode electrode foil for a solid electrolytic capacitor which is excellent in electrostatic capacity characteristics and ESR characteristics.

Etching foil on which a chemical conversion coating is formed on a surface and a coating made of metal carbide is further formed thereon, or plane foil on which a chemical conversion coating is formed on the surface and a coating made of metal carbide is further formed thereon is used as the cathode electrode foil for the solid electrolytic capacitor. Thus, when the foil is used for the solid electrolytic capacitor, it has excellent electrostatic capacitance characteristics and ESR characteristics.