A structure, in which a second treating unit group that performs, under vacuum or pressure, e.g., an electron beam or ultraviolet ray irradiation, a CVD or a cleaning treatment is provided integrally with a first treating unit group that forms an interlayer insulation film under a normal pressure, can shorten a treating time especially in a damascene process to decrease foot print per treating power. A treating time thus shortened can prevent an insulating film from absorbing moisture in the air that causes deterioration in film quality, and contribute to forming a quality insulation film even if a porous film, for example, is used as an insulation film.