An electrolyte material, which comprises a polymer having ion exchange groups converted from precursor groups in the following polymer., and having an ion exchange capacity of at least 1.35 meq/g dry resin: polymer: a polymer which has repeating units based on a perfluoromonomer having a precursor group of an ion exchange group and a dioxolane ring and repeating units based on a perfluoromonomer having no ion exchange group nor its precursor group and having a dioxolane ring, and which has a TQ as defined below of at least 200°C: TQ: a temperature at which the melt volume rate becomes 100 mm 3 /sec, when the polymer 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, wherein the ion exchange groups in the polymer are groups represented by the following formula: -(SO 2 X(SO 2 R f)a) - M + wherein M + is H +, a monovalent metal cation or an ammonium ion in which at least one hydrogen atom may be substituted by a hydrocarbon group, R f is a linear or branched perfluoroalkyl group which may have an etheric oxygen atom, and X is an oxygen atom, a nitrogen atom or a carbon atom, provided that when X is an oxygen atom, a=0, when X is a nitrogen atom, a=1, and when X is a carbon atom, a=2, at least one type of repeating units having ion exchange groups converted from the precursor groups in the repeating units are repeating units represented by the following formula: wherein R 1 is a bivalent perfluoroorganic group which may have an etheric oxygen atom, and each of R 2 to R 6 which are independent of one another, is a monovalent perfluoroorganic group which may have an etheric oxygen atom, or a fluorine atom, and at least one type of the repeating units are repeating units represented by the following formula: wherein each of R 7 to R 12 which are independent of one another, is a monovalent perfluoroorganic group which may have an etheric oxygen atom, or a fluorine atom. polymer: a polymer which has repeating units based on a perfluoromonomer having a precursor group of an ion exchange group and a dioxolane ring and repeating units based on a perfluoromonomer having no ion exchange group nor its precursor group and having a dioxolane ring, and which has a TQ as defined below of at least 200°C: TQ: a temperature at which the melt volume rate becomes 100 mm 3 /sec, when the polymer 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, wherein the ion exchange groups in the polymer are groups represented by the following formula: -(SO 2 X(SO 2 R f)a) - M + wherein M + is H +, a monovalent metal cation or an ammonium ion in which at least one hydrogen atom may be substituted by a hydrocarbon group, R f is a linear or branched perfluoroalkyl group which may have an etheric oxygen atom, and X is an oxygen atom, a nitrogen atom or a carbon atom, provided that when X is an oxygen atom, a=0, when X is a nitrogen atom, a=1, and when X is a carbon atom, a=2, TQ: a temperature at which the melt volume rate becomes 100 mm 3 /sec, when the polymer 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, wherein the ion exchange groups in the polymer are groups represented by the following formula: -(SO 2 X(SO 2 R f)a) - M + wherein M + is H +, a monovalent metal cation or an ammonium ion in which at least one hydrogen atom may be substituted by a hydrocarbon group, R f is a linear or branched perfluoroalkyl group which may have an etheric oxygen atom, and X is an oxygen atom, a nitrogen atom or a carbon atom, provided that when X is an oxygen atom, a=0, when X is a nitrogen atom, a=1, and when X is a carbon atom, a=2, at least one type of repeating units having ion exchange groups converted from the precursor groups in the repeating units are repeating units represented by the following formula: wherein R 1 is a bivalent perfluoroorganic group which may have an etheric oxygen atom, and each of R 2 to R 6 which are independent of one another, is a monovalent perfluoroorganic group which may have an etheric oxygen atom, or a fluorine atom, and at least one type of the repeating units are repeating units represented by the following formula: wherein each of R 7 to R 12 which are independent of one another, is a monovalent perfluoroorganic group which may have an etheric oxygen atom, or a fluorine atom.