NOVELTY - Ion conductor structural body (I) having a high ion conductivity and excellent mechanical strength, comprises a polymer matrix, a solvent capable of functioning as a plasticizer and an electrolyte.    USE - (I) is useful in a rechargeable battery, which is useful as power source for portable instruments which is small personal computers, word processors, video cameras, and cellular phones.    ADVANTAGE - (I) has high ion conductivity and excellent mechanical strength. (I) has improved charge-and-discharge efficiency.    DETAILED DESCRIPTION - Ion conductor structural body having a high ion conductivity and excellent mechanical strength comprises a polymer matrix, a solvent capable of functioning as a plasticizer and (c) an electrolyte, where: the polymer matrix comprises a polymer chain having at least a segment of formula (-(CH) (R1)-C(R2)(-A-R3)-) (A), a main chain portion of the polymer chain and a side chain portion of the segment having an orientation property, and the polymer matrix has a cross-linked structure of (I); and the ion conductor structural body includes a retaining material comprising at least one kind of a material which is a powdery resin material, a powdery glass material, a powdery ceramic material, a nonwoven fabric and a porous film.    R1, R2 = H or alkyl group of 2 or fewer carbon atoms;    A = group having at least a polyether group; and    R3 = group having at least an alkyl group of 6 or more carbon atoms (where R3 is a straight chain 6-22C alkyl group or 6-22C an alkyl benzyl and the a molecular weight ratio of the alkyl group of R3 to the polyether group of A is 0.05-3.0).    An INDEPENDENT CLAIM is included for a process for producing (I) comprising: mixing a monomer of formula CH(R1)=C(R2)(A-R3) (B), a solvent and an electrolyte to obtain a mixture; and subjecting the mixture to a polymerization treatment by way of a polymerization reaction to form a polymer matrix as the ion conductor structural body, where the weight ratio of the solvent to the polymer matrix is 1-20.    DESCRIPTION OF DRAWING(S) - The figure shows a process for producing ion conductor structural body.