A composition comprising a siloxane resin, a silicon compound substantially consisting of silicon, carbon and hydrogen, wherein the number ratio of carbon to silicon atoms forming an —X— bond (wherein X is (C)m (where m is an integer in the range of from 1 to 3), or a substituted or unsubstituted aromatic group with 9 or less carbon atoms) in the main chain of one molecule is in the range of from 2:1 to 12:1, and a solvent, is subjected to a heat treatment to form a low dielectric constant film. Accordingly, a low dielectric constant film having excellent resistance against chemicals and excellent moisture resistance is provided. A semiconductor integrated circuit having a fast response can be produced by using the film.