A resist underlayer film for a resist pattern formation by developing a resist with organic solvent after exposure of resist. Method for manufacturing a semiconductor includes: applying onto a substrate a resist underlayer film forming composition including hydrolyzable silanes, hydrolysis products of hydrolyzable silanes, hydrolysis-condensation products of hydrolyzable silanes, or a combination thereof. Hydrolyzable silanes being silane of Formulas (1), (2) and (3). Silane of Formulas (1), (2) and (3) in total silanes in a ratio % by mole of 45-90:6-20:0-35; baking the applied resist underlayer film forming composition to form a resist underlayer film; applying a composition to form a resist film; exposing the resist film to light; developing the resist film after exposure, with organic solvent to obtain patterned resist film; and etching the resist underlayer film by using the patterned resist film and processing the substrate using the patterned resist underlayer film; wherein Si(R1)4  Formula (1) R2[Si(R3)3]  Formula (2) R4[Si(R5)3]b  Formula (3).