The invention provides a fuel cell which comprises a solid polymer electrolyte sandwiched between a cathode to which an oxidizing agent gas is supplied and an anode to which a reducing agent gas is supplied, wherein at least one of the electrodes has an electroconductive organic polymer which has an oxidation-reduction function as an electrode catalyst. The invention further provides a fuel cell in which the electrode catalyst comprises a mixture of an electroconductive organic polymer and an inorganic oxidation-reduction catalyst, and has a higher output power.