An organosililane and a metal alkoxide mixed together at a given molar ratio are subjected to co-hydrolysis and polycondensation in a solution containing an organic solvent, water and a catalyst to obtain a precursor solution with a controlled inter-organosilane distance. The precursor solution is coated onto a solid surface, and then allowed to stand at room temperature under atmospheric pressure for a given time to obtain an organic/inorganic transparent hybrid film. A difference (hysteresis) between the advancing and receding contact angles of the hybrid film relative to a liquid having a surface tension of 18 to 73 dynes/cm has a smaller value than that of a surface treated by the organosilane alone. The hybrid film is improved in terms of adhesion, transparency, and the mobility of functional groups derived from the organosilane on the film surface. A solid surface can be covered by the organic/inorganic transparent hybrid film.