▎ 摘　　要

NOVELTY - A catalyst layer (30, 30') comprises a catalyst, a heat dissipation material, and an ionomer. USE - Catalyst layer used in membrane electrode assembly used for fuel cell (all claimed) e.g. polymer electrolyte fuel cell which is power generation system used for directly converting chemical reaction energy of hydrogen and oxygen in hydro-carbon substances e.g. methanol, ethanol and natural gas into electrical energy. ADVANTAGE - The catalyst layer suppresses deterioration of the membrane-electrode assembly due to an exothermic reaction. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) a membrane-electrode assembly (100); and (2) manufacture of the catalyst layer, which involves preparing an electrode slurry containing the catalyst, heat dissipation material, ionomer, and a dispersion medium, forming a slurry layer by coating the electrode slurry on a substrate and removing the dispersion medium from the slurry layer. DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of the membrane-electrode assembly. Anode (20) Cathode (20') Catalyst layers (30, 30') Electrode substrates (40, 40') Ion exchange membrane (50) Membrane-electrode assembly (100)