Electrolyte material, membrane electrode assembly and polymer electrolyte fuel cell

The present invention provides an electrolyte material which can form crack-resistant catalyst layers when used in membrane electrode assemblies and enables provision of fuel cells having good power generation characteristics, a membrane electrode assembly and a polymer electrolyte fuel cell. The electrolyte material of the present invention is made of a polymer having ion exchange groups comprising units based on tetrafluoroethylene, units having an ion exchange group and no cyclic ether structure, units having a cyclic ether structure and units based on a monomer having at least two polymerizable unsaturated bonds.