A method for film formation is provided that can significantly suppress the amount of a source gas consumed in the formation of a copper film on a substrate by supplying a gas of a metallic source material complex, for example, copper acetate, produced by the sublimation of a solid source material, as a source gas to the substrate to cause a chemical reaction of the source gas. A source gas produced by the sublimation of a solid source material is supplied into a processing chamber, and the source material is adsorbed as a solid onto an adsorption/desorption member within the processing chamber. Next, the source gas supply and exhaust are stopped, and the processing chamber is brought to the state of a closed space. Thereafter, the substrate is heated, and the source material is chemically reacted on the substrate to form a thin film on the substrate.