An electric insulation resistant coating has been developed by using photo-oxidized silicone oil. The silicone oil was exposed to ultraviolet⊈light in the air; which transformed the organic silicone oil into an inorganic amorphous glass film. Conventional large-area solar panels and smart papers are made of glass or plastic; in addition to being well insulated, waterproof, transparent, and hard, the panels are desirable to be light in weight and flexible. Here, metal foil is dipped into dimethylsiloxane silicone oil, and the silicone oil on the foil surface is irradiated with Xe2 excimer lamplight. Oxygen adsorbed on the sample surface is photo-excited by the irradiation to produce active oxygen. This active oxygen reacts with the silicone oil photo-excited and forms inorganic glass. With the process of the photo-oxidation, the silicone oil is vitrified, being inorganic.