Provided is an electrolyte membrane and a process of producing the same, wherein the electrolyte membrane predominantly comprises an unreinforced outer layer on one or each side of a reinforced inner layer, wherein the reinforced inner layer comprises an inner ion exchange resin reinforced with a non-woven fabric comprising a melt moldable fluororesin in the form of a continuous fiber, wherein some intersecting points of the continuous fiber are fused or bonded, and wherein the unreinforced outer layer comprises an outer ion exchange resin, which may be the same as or different from the inner ion exchange resin. The electrolyte membrane has high strength, excellent dimensional stability and low electric resistance and is therefore useful as a polymer electrolyte membrane for a membrane electrode assembly for a polymer electrolyte fuel cell having high output and excellent durability.