Abstract: Provided is a catalyst which does not corrode at high potentials or in acidic electrolytes of fuel cells, is stable, effectively participates in electrode reactions not only in a three-phase interface of a gas phase (humidified reaction gas) and a liquid phase formed in catalyst particles present on the surface in contact with an electrolyte membrane but also in a three-phase interface in catalyst particles in a catalyst layer present at positions away from the electrolyte membrane, has a high utilization efficiency of catalyst particles, has a high oxygen reduction ability, provides high characteristics, and is inexpensive compared to platinum. A fuel cell thus obtained has high characteristics and a long life, and is relatively inexpensive and excellent in economic efficiency.

Abstract: Provided is a catalyst which does not corrode at high potentials or in acidic electrolytes of fuel cells, is stable, effectively participates in electrode reactions not only in a three-phase interface of a gas phase (humidified reaction gas) and a liquid phase formed in catalyst particles present on the surface in contact with an electrolyte membrane but also in a three-phase interface in catalyst particles in a catalyst layer present at positions away from the electrolyte membrane, has a high utilization efficiency of catalyst particles, has a high oxygen reduction ability, provides high characteristics, and is inexpensive compared to platinum. A fuel cell thus obtained has high characteristics and a long life, and is relatively inexpensive and excellent in economic efficiency.