A film substrate of an electronic displaying element, an electronic optical element, a touch panel, or a solar battery is disclosed which is composed mainly of an organic polymer having water solubility of 0 to 5 g based on 100 g of 25.degree. C. water and having acetone solubility of 25 to 100 g based on 100 g of 25.degree. C. acetone and an inorganic condensation polymer of a reactive metal compound capable of being condensed.