To provide an electrolyte membrane for a direct methanol type fuel cell which is superior in methanol transmission resistance as a power source for a mobile phone or the like, and its manufacturing method.

The direct methanol type fuel cell that uses methanol as a fuel and generates electricity by electrochemical reaction by receiving supply of methanol comprises an electrolyte part 7 having positive ion conductivity with one face fitted with, for instance, a fuel electrode 8 and on the other fitted with, for instance, an air electrode 9. The electrolyte part 7 is constructed of a polymer thin film 1, in which a plurality of micropores 5 are provided, in which an electrolyte 11 is filled.