Abstract: The invention relates to a method for applying a coating composition to a substrate with a reverse roller coater so as to form a thin film on the substrate and then for baking the thin film so as to transform the thin film into a metal oxide film. The coating composition comprises: 0.1-10 wt % of at least one organic metal compound on a metal oxide basis; and at least one organic solvent. The at least one organic metal compound is selected from the group consisting of metal alkoxides, metal acetyl-acetonates and metallic soaps. The coating composition is adjusted to have a viscosity within a range from 0.1 to 100 centipoises. In this method, a reverse roller of the coater is rotated at a rotation speed within a range from 2 to 55 m/min. and the substrate is moved at a moving speed within a range from 1 to 30 m/min. while the coating composition is applied to the substrate. Furthermore, the rotation speed of the reverse roller is adjusted to be higher than the moving speed of the substrate.