MEMBRANE ELECTRODE ASSEMBLY

A membrane electrode assembly includes a solid polymer electrolyte membrane sandwiched between a pair of electrodes. Each of the electrodes has an electrode catalyst layer and a gas diffusion layer, the electrode catalyst layer facing the electrolyte membrane. A porous layer having a thickness of 5 to 40 μm and a seepage pressure of 10 to 60 kPa is interposed between the electrode catalyst layer and the gas diffusion layer. The porous layers preferably have a spring constant of 100 to 1000 GPa/m. The membrane electrode assembly may be devoid of any one of the porous layers.