TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Process: Inorganic-organic hybrid film is manufactured by solidifying mixture of tetra alkoxysilane and surface active agent prepared under acidic condition. The inorganic-organic hybrid film is heated to produce the inorganic porous membrane. A silane coupling agent is reacted with the pores and surface of the inorganic porous membrane, and the surface of the membrane is modified. The silane coupling agent contains the group which can be converted into proton electroconductive group.Preferred Compound: The silane coupling containing group which can be converted into proton electroconductive group is compound of formula XjRkSi((CH2)n-Y)m (I) or formula X3Si-(CH2)n-Y (II).X = alkoxy or halogen atom;R = alkyl group;Y = group which can be converted into a proton electroconductive group;m,j = 1-3;k = 0-2;n = 2-11;j+k+m = 4;X in formula (II) = 1-6C alkoxy or halogen atom;Y = -SH, -P(O)(OR1)(OR2) or -COOR3;R1-R3 = alkyl, aryl or aralkyl; andn in formula (II) = 2-8.Preferred Film: The inorganic porous membrane and proton electroconductive film has thickness of 1000 microns or less, central pore diameter of 1-50 nm, specific surface area of 200-800m2/g and pore volume of 0.1-1.0 cm3/g. EXAMPLE - Poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol)conjugated polymer (in g) (2.0) was dissolved in ethanol (15 g). Solution of 70 % nitric acid/water (1.487) was added followed by adding tetraethoxy silane (4.25). The mixture was stirred at 35-40 degrees C for 20 hours, poured into a dish and allowed to solidify at room temperature to form organic-inorganic hybrid film (0.497). The film was baked at 190 degrees C for 3 hours and porous membrane was formed. The porous membrane was immersed in a solution formed by adding dehydrated toluene to 3-mercapto propyl trimethoxy silane (0.12) at 100 degrees C for 20 hours. Thiol group was introduced on the inner surface of the pores of the porous membrane, and the porous membrane was modified. The thiol group was converted into sulfonic acid group using nitric acid solution. The film had proton electric conductivity of 2.7x10 to the power -3 S/cm at 85 degrees C and 94 % relative humidity, thickness of 0.6 mm and mean pore diameter of 5.8 nm.