TECHNOLOGY FOCUS - POLYMERS - Preferred Oligomer: The mercapto group containing oligomer (A) has several mercapto groups, and is a compound of formula (5 or 6).R7 = H, CH3, C2H5, C3H7 or C4H9;R8 = CH3, C2H5, C3H7, C4H9, C6H5, OH, OCH3, OC2H5, OC3H7 or OC4H9, and has branched structure which forms -OSi bonding partially or cyclic structure in a molecule, preferably OH, OCH3, OC2H5 or O-Si bonding;m = 1-20, preferably 3;n = 2-100, preferably 3-50;R9 = OH, OCH3, OC2H5, OC3H7, OC4H9, CH3, C2H5, C3H7, C4H9, C6H13, C8H17, C11H23, C12H25, C16H33, C18H37 or C6H5, and has branched structure which forms -OSi bonding partially or cyclic structure in a molecule, preferably OH, OCH3, OC2H5 or O-Si bonding;n in formula (6) = 1-100;t = 1-100; andn+t = 3-50.The oligomer (A) is obtained by hydrolyzing and condensing the composition containing mercapto group-containing alkoxy silane (C) of formula (2): (R3)t(R4)mSi-(CH2)n-SH.R3 = CH3, C2H5, C3H7, C4H9 or C6H5, preferably CH3;R4 = OCH3, OC2H5, OC3H7 or OC4H9, preferably OCH3 or OC2H5;t = 0-1, preferably 0, most preferably 1;m = 2-3, preferably 3, most preferably 2;m+t = 3; andn = 1-20, preferably 3.The raw material composition of oligomer (A), further contains at least one type of hydrolysability silyl compound (D) of formula (3): Si(R5)4, or at least one type of hydrolysability silyl compounds (E,G) of formulae (4,9): (R5)m(R6)nSi.R5 = Cl, OH, OCH3, OC2H5, OC3H7, OC4H9 or OCOCH3, preferably OCH3 or OC2H5;R6 = CH3, C2H5, C3H7, C4H9, C6H13, C8H17, C11H23, C12H25, C16H33, C18H37 or C6H5, preferably CH3;m in formula (4) = 2-3;n in formula (4) = 1-2;m+n = 4;m in formula (9) = 1-4, preferably 3-4; andn in formula (9) = 0-3, preferably 0-1.Preferred Method: At least one type of siloxane oligomer (H) of formula (10), at least one type of organic inorganic composite cross-linking agent (F) of formula (7) is mixed.X = Cl, OH, OCH3, OC2H5, OC3H7, OC4H9 or OCOCH3;R11 = CH3, C2H5, C3H7, C4H9 or C6H5;R12 = Cl, OH, OCH3, OC2H5, OC3H7, OC4H9, OCOCH3, CH3, C2H5, C3H7, C4H9, C6H13, C8H17, C11H23, C12H25, C16H33, C18H37 or C6H5, and has branched structure which forms -OSi bonding partially or cyclic structure in a molecule;m = 0-2;n = 1-100;X in formula (7) = Cl, OH, OCH3, OC2H5, OC3H7 or OC4H9, preferably OCH3 or OC2H5;R10 = 1-30C containing molecular chain group, preferably alkylene chain of formula -(CH4)n- (n = 1-30);R11 = CH3, C2H5, C3H7, C4H9 or C6H5; andm = 0, 1 or 2.The total additional amount of at least one type of compound chosen from cross-linking agent (F), hydrolysability metallic compound (G) and siloxane oligomer (H) is 200 weight parts or less, preferably 100 weight parts or less with respect to 100 weight parts of mercapto group containing oligomer (A). At the time of mixing oxidation decomposition, water solubility or hydrolysable micropore formation agent (B) after performing condensation reaction, oxidation decomposition, dissolution or hydrolysis, micropore formation agent is removed from a membranous gel, and micropore is formed at the surface and inner surface of the film. The micropore formation agent (B) is liquid water- soluble organic compound, or polyoxy alkylene, preferably polyethylene glycol having mean molecular weight of 100-600. The amount of micropore formation agent (B) is 3-150 weight parts with respect to 100 weight parts of oligomer (A).    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Catalyst: The catalyst is Broensted acid, base catalyst, preferably organic amines of at least one type of compound selected from triethyl amine, dipropyl amine, isobutyl amine, diethyl amine, diethyl ethanol amine, triethanol amine, pyridine and piperazine.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Catalyst: At least one type of compound chosen from potassium fluoride and ammonium fluoride is used as a catalyst. EXAMPLE - Mercapto group containing oligomer X-41-1805 (A-11) (in g) (2) having polymerization degree of 18 was dissolved in tetrahydrofuran (2 ml) and raw material solution was prepared. Triethyl amine (1) and water (0.2) were dissolved in tetrahydrofuran (1 ml) and set as catalyst solution. The raw material solution and catalyst solution were mixed with stirring for 16 minutes. The resulting solution was casted on a Teflon petri dish with internal diameter 8.4 cm, maintained at room temperature for 120 hours, 80degreesC saturated vapor for 12 hours and heated at 150degreesC for 12 hours. A transparent glass-like film was obtained. The obtained film was immersed in 1 N salt:acid at room temperature for 1 hour, and immersed in 80degreesC distilled water for 12 hours. The resulting film was immersed into mixed solvent of acetic acid (12.5 ml) and 30% hydrogen peroxide solution (10 ml) and heated at 60degreesC for 1 hour. The film was washed with 80degreesC distilled water for 3 hours and proton conductive film was obtained. The film had proton conductivity of 1.7x10-2 S/cm at 80degreesC and 95% relative humidity (Rh), and 2.2x10-2 S/cm at 120degreesC and 95% Rh, and drying-shrinkage ratio of 3.5, without shrinkage.