Disclosed is a metal separator for a solid oxide regenerative fuel cell coated with a conductive spinel oxide film. In the conductive spinel oxide film, yttrium is added to a manganese-cobalt spinel oxide to suppress growth of an insulating oxide film on the surface of the metal separator and volatilization of metal. In the conductive oxide film coated on the metal separator, yttrium is segregated at the grain boundaries of the spinel so that migration of oxygen through the grain boundaries can be suppressed. Therefore, the surface of the metal separator can be protected from exposure to the atmosphere and water vapor when the solid oxide regenerative fuel cell is operated at high temperature. In addition, poisoning of electrodes by metal volatilization from the surface of the metal separator and growth of an insulating oxide film on the surface of the metal separator can be prevented. Therefore, the stability of the solid oxide regenerative fuel cell stack can be markedly improved.