TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Component: The solvent is a nonprotic polar solvent comprising ethers, carbonates, nitriles, amides, esters, nitro compounds, sulfur compounds, and/or halogen compounds. The electrolyte is lithium salt.    TECHNOLOGY FOCUS - POLYMERS - Preferred Component: The ion conductor structural body includes a retaining material comprising a powdery resin material, a powdery glass material, a powdery ceramic material, a nonwoven fabric, and/or a porous film.Preferred Composition: The retaining material in the ion conductor structural body is 1-50 wt.% of a total amount of constituents of the ion conductor structural body.Preferred Process: A polymerization initiator is mixed in the first step. The process comprises forming a cross-linking structure in the polymer matrix by cross-linking reaction, where cross-linking structure comprises a covalent bond. A monomer capable of forming the cross-linking structure is mixed in the first step. The polymerization reaction includes the cross-linking reaction. A monomer of formula R4-CH=C(R5)-B (4) is mixed in the first step. The polymerization reaction utilizes heat energy.Preferred Parameter: The molecular weight ratio between the polyether group of A and the alkyl group of R3 is 0.1-1.0. A ratio of the number of carbon atoms in the alkyl group of R3 and n is 0.05-10, preferably 0.5-5.0. Preferred Definitions:    B=a group comprising -(CH2-CH(CH3)-O)n-Z, -(CH2-CH2-O)m-(CH2-CH(CH3)-O)n-Z, -(CH2-CH(CH3)-O)m-(CH2-CH2-O)n-Z, -(CH2-CH2-O)k-(CH2-CH(CH3)-O)m-(CH2-CH2-O)n-Z, -(CH2-CH(CH3)-O)k-(CH2-CH2-O)m-(CH2-CH(CH3)-O)n-Z, or preferably -(CH2-CH2-O)n-Z;    k, m, n=positive integer;    Z=H or alkyl group of 1-4C atoms;    n=2-100;    R3 (in formula (3))=straight chain alkyl group of 8-18C atoms;    A (in formula (3))=a group comprising -(CH2-CH(CH3)-O)n-, -(CH2-CH2-O)m-(CH2-CH(CH3)-O)n, or preferably -(CH2-CH2-O)n-;and    n=2-100, preferably 5-30.    EXAMPLE - n-Dodecylpolyethyleneglycol (the number of ethyleneoxide group: 20) acrylate (5 pbw) having an alkyl group of 12C atoms as the first monomer whose side chain having an alkyl group and a polyether group; polyethyleneglycol (the number of ethyleneoxide group: 9 ) methylmethacrylate (6 pbw) as the second monomer; and polyethyleneglycoldimethacrylate (the number of ethyleneoxide group: 13) (0.2 pbw) as the third monomer as a cross-linking agent were added to an electrolyte solution obtained by mixing propylene carbonate (61 pbw), ethylene carbonate (61 pbw), and lithium tetrafluoroborate (13 pbw) as an electrolyte to obtain a mixture. The resultant mixture was heated to 40degreesC and well agitated so that the ingredients were homogeneously dissolved in the solution to obtain a mixture solution. As a radical polymerization initiator, azobisisobutylonitrile (0.002 pbw) was added to the mixture solution. Then the mixture solution was introduced into a cell formed by arranging two quartz glass plates whose one side face having a fluororesin layer, such that their fluororesin layer-bearing faces are opposed to each other while forming a gap with a thickness of 50 microns between them and sealing their periphery by a spacer made of Teflon(RTM: PTFE). The cell was heated at 70degreesC for 1 hour, where mixture solution in the cell was subjected to a polymerization treatment via a polymerization reaction, where polymerized product was formed in the cell. The polymerized product was taken out from the cell to obtain a film-like ion conductor structural body. The ion conductivity at 25 and -20degreesC was 1. The anisotropic ion conductivity was 9.