A membrane-electrode assembly for a solid polymer electrolyte fuel cell is provided that uses a proton conductive membrane having high proton conductivity and also superior heat resistance and chemical durability. A membrane-electrode assembly for a solid polymer electrolyte fuel cell is provided with an anode on one side of a proton conductive membrane and a cathode on another side thereof, and the proton conductive membrane is a sulfonated polyarylene containing a structure expressed by the general formula (1) below: —Rs—Z—Rh  (1) In the formula (1), Z represents at least one structure selected from the group consisting of —CO—, —SO2—, and —SO—; Rs represents a direct bond or any divalent organic group; and Rh represents a nitrogen-containing heterocyclic group.