The invention relates to a method for producing a bag (25,40) made of a polymer and/or metal film material. Said bag (25,40) is closed at the bottom end thereof and is provided with four outer walls (A-D) that are connected by means of four seams (27). The novelty of the invention lies in the fact that the material (A-E) needed to make the bag is fed to an unwinding device of a bottom-forming apparatus in the form of a film tube (25, 40) that is coiled on a reel while the bottom-forming apparatus separates the unwound tube into tube parts and seals at least one end of the bag.
