An object is to provide a solid polymer electrolyte membrane for solid polymer electrolyte fuel cell, which has high durability, as well as a membrane electrode assembly and a solid polymer electrolyte fuel cell, each containing the same. The solid polymer electrolyte membrane is produced using polymer electrolyte-containing solution preparation step of dissolving a perfluorocarbonsulfonic acid resin (component A) having an ion-exchange capacity of 0.5 to 3.0 meq/g, a polyazole-based compound (component B) and an alkali metal hydroxide in a protic solvent to prepare a polymer electrolyte-containing solution in which a weight ratio of the component A to component B, (A/B), is from 2.3 to 199 and a total weight of the component A and the component B is from 0.5 to 30% by weight. In a membrane formation step, a membrane is formed from the polymer electrolyte-containing solution.