A solid polymer fuel cell has a plurality of stacked single battery modules having an electrolyte membrane, electrode layers disposed on both surfaces of the electrolyte membrane, and a pair of separators provided with a gas flow paths disposed on the inside surface so as to sandwich the electrode layer. The electrolyte membrane is provided with electrolyte material and a nonwoven fabric which is embedded in the electrolyte material. The nonwoven fabric is provided with a plurality of fused parts that are provided in a linear shape or spotted on a part of the nonwoven fabric that is a part corresponding to of the solid polymer fuel cell. Two or more nonwoven fibers are fused to each other, and the thickness thereof is thinner than the membrane thickness of the unwoven fabric.