TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Component: The phosphoric acid group-containing unsaturated monomer has 2 hydroxyl groups per monophosphate group. The phosphoric acid group-containing unsaturated monomer is of formula (1). The amino group-containing unsaturated monomer is of formulae (2-6), and is a heterocyclic ring-like amine compound having one or more vinyl group.R1=H or alkyl group, preferably H or methyl group;R2=H or (un)substituted alkyl group, preferably H, methyl or methylene chloride;n=1-6;R4,R5,R7,R8, R10,R11,R13,R14,R17=H, 1-4C alkyl or 6-10C aryl group;R3,R6,R9,R12,R15,R16=H or methyl group;X1=-O- or -NH- group;andY1-Y4=(un)substituted 1-6C alkylene or (un)substituted 1-16C arylene group.The other unsaturated monomer (X) is an unsaturated monomer (d) having functional group(s) and ethylenically unsaturated bond(s) in a molecule, and/or an unsaturated monomer (e) ethylenically unsaturated bond(s) in a molecule and does not have functional group. Monomer (X) is of formulae (8-10). The unsaturated monomer having functional group has functional group(s) chosen from phosphoric acid residue, sulfonic acid group, carboxylic acid group and alcoholic hydroxyl group. The unsaturated monomer which do not have functional group are (meth)acrylonitrile, (meth)acrylic acid ester, (meth)acrylic acid amid, (un)substituted styrene, vinyl and fluorine group-containing unsaturated monomer having fluorine group(s) and ethylenically unsaturated bond(s) in a molecule. The other unsaturated monomer is a fluorine group-containing unsaturated monomer chosen from fluorine group-containing (meth)acrylic acid ester having fluorine group(s), fluorine group-containing (meth)acrylic acid having fluorine group(s), fluorine group-containing olefin-type unsaturated monomer having fluorine group-containing alkyl group and/or fluorine group(s), and ethylenically unsaturated bond, and fluorine group-containing diene group unsaturated monomer having alkylene group containing fluorine group(s), and 2 ethylenically unsaturated bonds. Monomer (X) contains phosphoric acid group-containing diester group unsaturated monomer of formula (7). The fluorine group-containing (meth)acrylic acid ester is of formula (11). The fluorine group-containing (meth)acrylic acid is of formula (12). The fluorine group-containing olefin-type unsaturated monomer is of formulae (13,14). The fluorine group-containing diene group unsaturated monomer is of formula (15). The quaternary ammonium salt group-containing unsaturated monomer is of formulae (16-20).R18,R21=same as R1;R19,R20=same as R2;m,p=1-6;R22-R24=same as R3;Y5,Y6=same as Y1;X2=same as X1;X3,X8-X10=H, fluorine group, fluorine group-containing methyl group having fluorine group(s), or methyl group;R25=fluorine group-containing alkyl group having fluorine group(s), or alkyl group;X4=fluorine group-containing methyl group having fluorine group(s), or methyl group;Rf1=alkyl group containing fluorine group(s);X5-X7,X12-X17=H or fluorine group;X11=methyl group having fluorine group and halogen, alkoxy group optionally having fluorine group, alkyl group or hydrogen;andRf2=alkylene group having fluorine group(s).Preferred Composition: Ratio of amino group of amino group-containing unsaturated monomer with respect to phosphoric acid group of phosphoric acid group-containing unsaturated monomer is 50-180 mol%.    TECHNOLOGY FOCUS - POLYMERS - Preferred Process: The monomer composition is polymerized by irradiating with an ultraviolet ray, and the solid polymer electrolyte is obtained. EXAMPLE - Phosmer PP (acid-phosphoxy polyoxypropylene glycol methacrylate) (in g) (77.3) was dissolved in water (0.77) and methanol (350 ml) at room temperature. N,N-dimethyl amino ethyl methacrylate (28.3) was dripped over the obtained solution, and stirred until pH became 5.5. The reaction solution was concentrated at 40degreesC under reduced pressure. The obtained monomer composition had double bond purity of 86.4% and acid value of 127 mgkOH/g. The composition had half salt of formula (27) (n=5-6) as main component. The monomer composition was casted on a glass flat plate having fluororesin film, and photopolymerized by irradiating with an ultraviolet ray (15-30 muW/cm2) for 7-8 minutes. Thus, a solid polymer electrolyte film having thickness of 148 microns was produced. The electrolyte film had favorable methanol-proof property and proton conductivity.