According to the present invention, there is provided a semiconductor device fabrication method comprising: forming a first insulating film on a semiconductor substrate; forming a conductive layer on the first insulating film; exposing the first insulating film by removing a portion of the conductive layer; forming a second insulating film on the exposed surface of the first insulating film in a first processing chamber isolated from an outside; performing a modification process on the second insulating film in the first processing chamber, and then unloading the semiconductor substrate from the first processing chamber to the outside; and annealing the second insulating film in a second processing chamber.