Disclosed is a filming method for forming a thin film on a treating object (W) which has an insulating layer (4) formed with a recess (6) on its surface. In the filming method, there are sequentiallyexecuted the barrier layer forming step of forming a Ti-containing barrier layer (12) on the surface of the treating object including the surface in the recess, the seed layer forming step of forminga Ru-containing seed layer (16) over the barrier layer by a CVD, and the auxiliary seed layer forming step of forming a Cu-containing auxiliary seed layer (164) over the seed layer by a sputtering. All over the surface of the treating object, therefore, a sufficient padding can be made on either the recess having a small line width or hole diameter or the recess having a high aspect ratio.