Method of manufacturing a membrane electrode assembly and a membrane electrode assembly, a polymer electrolyte fuel cell

A diffusion of the reaction gases to increase the water holding property without inhibiting the like generated removal of water in the electrode reaction, to provide a membrane electrode assembly comprising an electrode catalyst layer exhibiting high power generation characteristics even under low humidified conditions it, and it is an object to provide a manufacturing method thereof. The present invention provides a membrane electrode assembly was sandwiched a polymer electrolyte membrane a pair of electrode catalyst layers, wherein the electrode catalyst layer comprises particles carrying a polymer electrolyte and a catalyst material, and the electrode catalyst layer in, are increasing diameter 1.0μm or less of pore volume in terms of by cylindrical approximation of the pores determined by the mercury intrusion porosimetry toward the electrode catalyst layer surface is outside the polymer electrolyte membrane is the inner it was a membrane electrode assembly according to claim. .FIELD 1