PURPOSE: To increase the amount of metal phthalocyanine supported on carbon by one time operation, by immersing carbon in a solution prepared by dissolving metal phthalocyanine in acid, and depositing the metal phthalocyanine on the carbon by diluting the solution with water.

CONSTITUTION: Carbon is immersed in a solution prepared by dissolving metal phthalocyanine in acid, and the metal phthalocyanine is deposited on the carbon by diluting the solution with water. Copper phthalocyanine, cobalt phthalocyanine, or nickel phthalocyanine is preferable as the metal phthalocyanine. Sulfuric acid, chlorosulfonic acid, and phosphoric acid dissolve metal phthalocyanine well. High concentrated acid dissolves metal phthalocyanine well. As the carbon material, acetylene black, carbon black such as furnace black, and activated carbon prepared from organic waste and others are preferable.