NOVELTY - An inorganic layer(s) (14) containing silicon compound is formed on support (B) by gas-phase depositing method, and the surface of inorganic layer is exposed to air. An organic layer (12) comprising 2 or more layers are formed on inorganic layer by coating method. The coating material which does not contain pH adjuster, is applied to the surface of inorganic layer, heat-processed at high temperature and dried, to obtain functional film (10a,10b,10c). The organic layer comprises organic compound containing silane coupling agent with a concentration of 0.1-25 wt.%.    USE - Manufacture of functional film used as optical film for optical filter, gas-barrier film, and light reflection-prevention film. Uses include but are not limited to packaging material for foodstuffs, liquid crystal display device, organic electroluminescent display, semiconductor device and solar cell.    ADVANTAGE - The method provides high efficient functional film having high gas-barrier performance, and high adhesiveness between organic and inorganic layer.    DETAILED DESCRIPTION - An inorganic layer(s) containing silicon compound is formed on the support by gas-phase depositing method, and the surface of inorganic layer is exposed to air. An organic layer comprising 2 or more layers are formed on the inorganic layer by coating method. The coating material which does not contain pH adjuster, is applied to the surface of inorganic layer, heat-processed at high temperature and dried, to obtain functional film. The organic layer comprises organic compound containing silane coupling agent with a concentration of 0.1-25 wt.%, excluding organic solvent. The drying process is performed at high temperature or the boiling point of byproduct and the boiling point of the organic solvent are higher than the azeotropic point of the by-product and organic solvent. An INDEPENDENT CLAIM is included for functional film, containing support, organic layer and inorganic layer including silicon nitride in which oxygen group and hydroxyl group are introduced on the surface of inorganic layer.    DESCRIPTION OF DRAWING(S) - The drawings show a schematic view of functional film.    Functional films (10a,10b,10c)    Organic layer (12)    Inorganic layer (14)    Protective organic layer (16)    Support (B)