A method for manufacturing a semiconductor device includes the steps of: (a) forming a low dielectric constant film over a semiconductor substrate; (b) forming a recess in the low dielectric constant film; (c) after the step (b), sequentially performing the steps of (c1) applying an organic solution to the low dielectric constant film and (c2) silylating the low dielectric constant film with a silylating solution; and (d) after the step (c), embedding a metal in the recess to form at least one of a via plug and a metal wiring in the low dielectric constant film. Performing the step (c1) before the step (c2) improves a penetration property of the silylating solution into the low dielectric constant film.