NOVELTY - The proton conductive film has a continuous structure of silicon-oxygen cross-linked microparticles (1) having sulfonic acid group, on the surface. Pores are formed in the film between the microparticles. The total pore volume of pore is below 0.3 cm3/g measured by BET method. The proton conductive film has ion exchange capacity of 0.7 meq/g or more.    USE - For fuel cell (claimed).    ADVANTAGE - The proton conductive film has excellent heat resistance and proton conductive capability under high temperature and low humidity. Fluctuation of proton conduction capability by humidity change, is prevented.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) complex proton conductive film obtained by composite reinforcement of proton conductive film to a polymeric material;    (2) manufacture of proton conductive film. A mercapto group-containing compound which has a mercapto group, covalent-bonded hydrolysable silyl group which can carry out condensing reaction and/or a silanol group, is prepared. Water and catalyst are added to the compound and viscosity is increased by condensation hydrolysis. A film which consists of continuous structure of silicon-oxygen cross-linked microparticles, is formed by heating and baking the hydrolysable silyl group. The mercapto group in the film is oxidized and a sulfonic acid group is formed. The sulfonic acid group is introduced to the surface of silicon-oxygen cross-linked structure microparticle;    (3) manufacture of complex proton conductive film which involves impregnating a porous material which consists of fluorine resin into the film which consists of continuous structure of silicon-oxygen cross-linked microparticles; and    (4) fuel cell using the proton conductive film or complex proton conductive film.    DESCRIPTION OF DRAWING(S) - The figure shows the model which shows the structure of the proton conductive film.    microparticle which consists of silicon-oxygen cross-linked structure (1)    gaps (2)