In the formation of a halftone type phase shift mask, a reactive gas introduction inlet and an inert gas introduction inlet are provided so as to introduce the respective gases separately and by using a reactive low throw sputtering method a molybdenum silicide based phase shifter film is formed. Thereby, it becomes possible to provide a halftone type phase shift mask, which is applicable to an ArF laser or to a KrF laser, by using molybdenum silicide based materials.