An electrolyte material which is formed of a polymer (H) obtained by converting precursor groups in the following polymer (F) to ion exchange groups: Polymer (F): a polymer consisting of: structural units (A) based on a perfluoromonomer having a precursor group represented by the following formula (g1), structural units (B) represented by the following formula (u2), structural units (C) based on tetrafluoroethylene, and optionally structural units (D) based on chlorotrifluoroethylene, trifluoroethylene, vinylidene fluoride, vinyl fluoride, ethylene, propylene, perfluoro(3-butenyl vinyl ether), perfluoro(allyl vinyl ether), a perfluoro α-olefin, a (perfluoroalkyl)ethylene, a (perfluoroalkyl)propene, a perfluoro(alkyl vinyl ether) or the following monomer (m3) CF 2 =CF(CF 2 ) s OCF 2 -CFZ-Q-SO 2 F (m3) wherein Q is a single bond or a perfluoroalkylene group which may have an etheric oxygen atom, Z is a fluorine atom or a monovalent perfluoro organic group, and s is 0 or 1, wherein the proportion of the structural units (A) is from 8 to 19 mol%, the proportion of the structural units (B) is from 65 to 80 mol%, and the proportion of the structural units (C) is from 1 to 27 mol%, in 100 mol% of all structural units: wherein Q 1 is a perfluoroalkylene group which may have an etheric oxygen atom, Q 2 is a single bond or a perfluoroalkylene group which may have an etheric oxygen atom, and Y is a fluorine atom or a monovalent perfluoro organic group. wherein each of R 11 and R 12 which are independent of each other, is a fluorine atom or a C 1-5 perfluoroalkyl group, and each of R 13 and R 14 which are independent of each other, is a fluorine atom, a C 1-5 perfluoroalkyl group or a C 1-5 perfluoroalkoxy group, and wherein the following TQ value of the polymer (F) is from 255 to 300°C: TQ value: a temperature at which the extrusion rate becomes 100 mm 3 /sec, when the polymer (F) is subjected to melt-extrusion under an extrusion pressure condition of 2.94 MPa from a nozzle having a length of 1 mm and an inner diameter of 1 mm. structural units (A) based on a perfluoromonomer having a precursor group represented by the following formula (g1), structural units (B) represented by the following formula (u2), structural units (C) based on tetrafluoroethylene, and optionally structural units (D) based on chlorotrifluoroethylene, trifluoroethylene, vinylidene fluoride, vinyl fluoride, ethylene, propylene, perfluoro(3-butenyl vinyl ether), perfluoro(allyl vinyl ether), a perfluoro α-olefin, a (perfluoroalkyl)ethylene, a (perfluoroalkyl)propene, a perfluoro(alkyl vinyl ether) or the following monomer (m3) CF 2 =CF(CF 2 ) s OCF 2 -CFZ-Q-SO 2 F (m3) wherein Q is a single bond or a perfluoroalkylene group which may have an etheric oxygen atom, Z is a fluorine atom or a monovalent perfluoro organic group, and s is 0 or 1, wherein the proportion of the structural units (A) is from 8 to 19 mol%, the proportion of the structural units (B) is from 65 to 80 mol%, and the proportion of the structural units (C) is from 1 to 27 mol%, in 100 mol% of all structural units: wherein each of R 11 and R 12 which are independent of each other, is a fluorine atom or a C 1-5 perfluoroalkyl group, and each of R 13 and R 14 which are independent of each other, is a fluorine atom, a C 1-5 perfluoroalkyl group or a C 1-5 perfluoroalkoxy group, and wherein the following TQ value of the polymer (F) is from 255 to 300°C: TQ value: a temperature at which the extrusion rate becomes 100 mm 3 /sec, when the polymer (F) is subjected to melt-extrusion under an extrusion pressure condition of 2.94 MPa from a nozzle having a length of 1 mm and an inner diameter of 1 mm. <EOS>