A diamond electrode having a prolonged life by combining a conventional
diamond electrode having a relatively short life with other components is
provided. A diamond electrode for electrolysis includes an electrode
substrate, at least the surface of which comprises Magneli phase titanium
oxide, and conductive diamond supported as an electrode catalyst on a
surface of the electrode. The electrode catalyst may contain a titanium
oxide powder. Magneli phase titanium oxide improves conductivity without
forming a stable oxide layer on the substrate surface.