a method for manufacturing a semiconductor device wherein a contact hole formed in an interlayer insulating film on a semiconductor substrate is filled with a plug for electrically connecting an overlying conductor layer with an underlying conductor layer . the plug fills the contact hole , and comprised a tungsten film the upper end whereof is positioned below the upper surface of the interlayer insulating film , and a tungsten film which is filled on the tungsten film in the contact hole and the upper surface whereof is on substantially the same level as the upper surface of the interlayer insulating film .