ELECTRODE CATALYST LAYER, MEMBRANE ELECTRODE ASSEMBLY AND POLYMER ELECTROLYTE FUEL CELL

Provided are an electrode catalyst layer, a membrane electrode assembly and a polymer electrolyte fuel cell, having sufficient drainage property and gas diffusibility with high power generation performance over a long term. An electrode catalyst layer () bonded to a surface of a polymer electrolyte membrane () includes at least a catalyst substance (), a conductive carrier (), a polymer electrolyte () and fibrous substances (). The number of the fibrous substances () in which inclination θ of axes with respect to a surface of the electrode catalyst layer () bonded to the surface of the polymer electrolyte membrane () is 0° ≤θ