| abstract |
A membrane catalyst layer assembly for realizing a polymer electrolyte fuel cell having an initial characteristic not degrading, exhibiting an adequate cell performance for a long term, and having an excellent durability. At least in the cathode catalyst layer, the ratio (Wp/WCat-C) of the mass Wp of the polymer electrolyte to the mass WCat-C of the catalyst-supporting carbon is decreased from the innermost layer disposed nearest to the polymer electrolyte membrane to the outermost layer disposed farthest from the polymer electrolyte membrane. The ratio (Wp/WCat-C) in the innermost layer is 0.8 to 3.0, and the ratio (Wp/WCat-C) in the outermost layer is 0.2 to 0.6. |