The present invention provides a polymer electrolyte fuel cell, which is inexpensive and has an excellent efficiency of generating electric power, by using a material alternative to a perfluoroalkylene sulfonic acid polymer. The polymer electrolyte fuel cell comprises a pair of electrodes (2, 3) consisting of an oxygen electrode (2) and a fuel electrode (3) both having a catalyst layer (5) containing a catalyst and an ion conducting material; and a polymer electrolyte membrane (1) sandwiched between the two catalyst layers (5) of the both electrodes (2, 3). The above ion conducting material contained in the above polymer electrolyte membrane (1) or in the catalyst (5) layer of at least one of the above electrodes (2, 3) comprises a sulfonated polyarylene having sulfonic acid side-chain groups.