Provided is an ionomer resin including a copolymer containing the following first structural unit. L1 to L5 are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkanol group having 1 to 4 carbon atoms, or a specific functional group including an anion-exchange group, and an example of the functional group is —Z2-M1-Z1(R1)(R2)(R3). R1 to R3 are directly bonded to Z1 and are each independently an alkyl group having 1 to 8 carbon atoms or an alkanol group having 1 to 8 carbon atoms. M1 is a linear hydrocarbon chain having 3 to 8 carbon atoms, Z1 is a nitrogen atom or a phosphorus atom, and Z2 is a nitrogen atom bonded to one hydrogen atom, an oxygen atom, or a sulfur atom. L6 is a hydrogen atom, a methyl group, or an ethyl group.