Patent ID: 7645534

Claim:
A membrane-electrode assembly for solid polymer electrolyte fuel cells, comprising: an anode electrode, a cathode electrode, and a proton conductive membrane, the anode electrode and the cathode electrode being disposed on opposite sides of the proton conductive membrane, wherein the proton conductive membrane includes a polyarylene having the constitutional unit (S) expressed by the general formula (2-2) described below and the constitutional unit (T) expressed by the general formula (2-3) described below; the ratio s of the unit (S) in the polyarylene is 50 to 95 mole %, and the ratio t of the unit (T) is 5 to 50 mole % in the polyarylene, where s+t=100 mole %, in which, A independently represents at each occurrence independently a divalent linking group expressed by —CO— or —SO 2 —, and R 1 to R 4 independently represent at each occurrence a hydrogen atom, fluorine atom, alkyl group, or aryl group.