A sacrificial film-forming composition is provided comprising (A) an organofunctional silicone resin which is a co-hydrolytic condensate of hydrolyzable silanes having formula (1) and formula (2) and/or (3): X--Y--SiZ.sub.3 (1) R.sub.nSiZ.sub.4-n (2) P--SiZ.sub.3 (3) wherein Z is a hydrolyzable group, X is a crosslinkable organofunctional group, Y is a single bond or a divalent hydrocarbon group, R is hydrogen or a monovalent hydrocarbon group, n is an integer of 0-3, and P is a substituent group which readily decomposes and volatilizes upon thermal decomposition, (B) a crosslinking agent, (C) an acid generator, (D) an extender or porogen, and (E) an organic solvent. The composition has improved storage stability, filling properties, adhesion and coating uniformity sufficient to form a sacrificial film which is effectively dissolvable in a stripping solution.