Polymer electrolyte membrane for a fuel cell, fuel cell membrane comprising the same - a fuel cell system including the electrode assembly, and this

The polymer electrolyte membrane of the present invention includes a proton conductive cation exchange resin, a non-proton-conductive polymer, and an inorganic additive. The inorganic additive is adapted to inhibit a phase separation between the proton conductive cation exchange resin and the non-proton-conductive polymer.