Disclosed is a coating composition for use in producing an insulating thin film, comprising: (A) at least one silica precursor comprised of at least one compound selected from the group consisting of an alkoxysilane and a hydrolysis product thereof; (B) at least one organic polymer; (C) water; (D) at least one alcohol; and optionally (E) an organic solvent for a mixture of the components (A), (B), (C) and (D); wherein the weight ratio (WR) of the water (C) to the at least one silica precursor (A) satisfies the formula 0.01