A method for manufacturing a semiconductor device includes forming an insulating film including silicon, oxygen, carbon and hydrogen above a semiconductor substrate, forming a wiring trench in the insulating film, forming a metal film to be a metal wiring on the insulating film such that the metal film is provided in the wiring trench, forming the metal wiring by removing the metal film outside the wiring trench, performing a hydrophobic treatment to the surface of the insulating film after the forming the metal wiring, and forming a metal cap selectively on an upper surface of the metal wiring by plating after the performing the hydrophobic treatment.