Patent ID: 7727649

Claim:
A polymer electrolyte fuel cell, comprising: a humidifier; and a fuel cell stack, the fuel cell stack including plural cells each containing: a pair of electrodes, and a proton-conductive electrolyte membrane arranged between the pair of electrodes, wherein an oxidant gas or a fuel gas passes through the humidifier before feeding to the fuel cell stack, and a wet gas containing water or water vapor passes through the humidifier, wherein the humidifier includes a porous separating layer and a hydrophilic water-releasing layer, wherein the separating layer has pores having an average pore diameter of 0.01 to 0.1 μm and is configured to separate the wet gas from the oxidant gas or the fuel gas in the humidifier and allow transit of moisture through the pores in the vapor phase, and wherein the hydrophilic water-releasing layer has pores in which moisture is retained in the liquid phase having an average pore diameter of 1 to 100 μm and is disposed in a side of the oxidant gas or the fuel gas to the separating layer in the humidifier.