To prevent generation of wrinkles by reducing the tension applied to a film in delivering the film, and to deliver the film of the constantly appropriate quantity.

An untreated material intermittently rotating mechanism 14 delivers a strip-like film 12 of one bag from an untreated material roll 10 based on the preset value corresponding to the length of one bag, and holds the untreated material roll 10 in a stopped condition. the strip-like film 12 delivered by the untreated material intermittently rotating mechanism 14 is stored in a tension mechanism 48 with a specified tension applied thereto. A cylindrical film 12a formed cylindrical by a bag manufacturing machine 16 is delivered downward along a filling cylinder 40 by a cylindrical film delivering mechanism 18 by the length corresponding to the strip-like film 12 of one bag which is delivered from the untreated material roll 10 in advance.