A proton conducting polymer having a repeating unit given by formula (1) below is provided. ##STR00001## A proton conducting polymer membrane manufactured using the proton conducting polymer can be more easily manufactured than a conventional fluorine-based membrane and can be commercialized as an automobile fuel cell due to its low cost of production. Also, the proton conducting polymer membrane has high moisture content and does not cause the water flooding at high current density, thereby improving the efficiency of a cell. In addition, the proton conducting polymer membrane enables a fuel cell to stably operate at temperatures of 100.degree. C. or higher, thereby preventing the poisoning of a catalyst and extending the lifetime of the fuel cell.