TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: Element (M) is chosen from tantalum, zirconium, titanium, iron, tungsten, molybdenum, cerium and aluminum. The metal oxycarbonitride is of formula: ZraMbCxNyOz or TiaMbCxNyOz.a=0.01 or more to less than 1;b=greater than 0 to 0.99 or less;x,y=0.01-2;z=0.01-3;a+b=1;andx+y+z=5 or less.The catalyst layer further includes electroconductive particles. Preferred Process: The metal carbonitride is obtained by: (i) heating a mixture (compound(s) containing element (M) and zirconium is taken as carbide) of compound containing element (M) (except zirconium), and compound containing zirconium in inert gas containing nitrogen gas, or nitrogen; (ii) heating a mixture (compound(s) containing element (M) and titanium is taken as carbide) of compound containing element (M) (except titanium), and compound containing titanium in inert gas containing nitrogen gas, or nitrogen; (iii) heating a mixture of oxide of element (M) (except zirconium), zirconium oxide, and carbon in inert gas containing nitrogen gas, or nitrogen; (iv) heating a mixture of oxide of element (M) (except titanium), titanium oxide, and carbon in inert gas containing nitrogen gas, or nitrogen; (v) heating a mixture of oxide of element (M) (except zirconium), zirconium carbide, and zirconium nitride in inert gas containing nitrogen gas, or nitrogen; (vi) heating a mixture of oxide of element (M) (except titanium), titanium carbide, and titanium nitride in inert gas containing nitrogen gas, or nitrogen; (vii) heating a mixture of oxide of element (M) (except zirconium), zirconium carbide, zirconium nitride, and zirconium oxide in inert gas containing nitrogen gas, or nitrogen; (viii) heating a mixture of oxide of element (M) (except titanium), titanium carbide, titanium nitride, and titanium oxide in inert gas containing nitrogen gas, or nitrogen; (ix) heating a mixture of carbide of element (M) (except zirconium), nitride of element (M) (except zirconium), and zirconium oxide in inert gas containing nitrogen gas, or nitrogen; (x) heating a mixture of carbide of element (M) (except titanium), nitride of element (M) (titanium), and titanium oxide in inert gas containing nitrogen gas, or nitrogen; (xi) heating a mixture of carbide of element (M) (except zirconium), and zirconium nitride in inert gas containing nitrogen gas, or nitrogen; (xii) heating a mixture of carbide of element (M) (except titanium), and titanium nitride in inert gas containing nitrogen gas, or nitrogen; (xiii) heating a mixture of nitride of element (M) (except zirconium), and zirconium carbide in inert gas containing nitrogen gas, or nitrogen; or (xiv) heating a mixture of nitride of element (M) (except titanium), and titanium carbide in inert gas containing nitrogen gas, or nitrogen. Preferred Conditions: The heating temperature of process (i) is 600-2200 degrees C. Heating process (X) is carried out at 400-1400 degrees C in an inert gas having an oxygen concentration of 0.1-10 vol.% and a hydrogen-gas concentration of 0.01-5 vol.%.