The present invention provides a method for manufacturing a semiconductor device, comprising: forming a contact sacrificial pattern on a substrate to cover source and drain regions and expose a gate region; forming an interlayer dielectric layer on the substrate to cover the contact sacrificial pattern and expose the gate region; forming a gate stack structure in the exposed gate region; removing the contact sacrificial pattern to form the source/drain contact trench; and forming a source/drain contact in the source/drain contact trench. By means of a contact sacrificial layer process, the method of manufacturing a semiconductor device according to the present invention effectively reduces the distance between the gate spacer and the contact region and increases the area of the contact region, thus effectively reducing the parasitic resistance of the device.