Abstract: A stuffer nozzle of a double pipe type is inserted in a cylindrical member formed by joining opposite ends of a film. Fluid material such as raw egg is supplied from an inner pipe of the stuffer nozzle to fill the cylindrical member with the fluid material. An air valve communicating with an outer pipe of the stuffer nozzle is opened to exhaust air in the cylindrical member and reduce pressure in the cylindrical member in synchronism with a timing that a pair of squeezing rollers squeeze the cylindrical member filled with the fluid material. The squeezed cylindrical member is clamped by a clamping member. The air vent valve is closed to prevent air from entering into the cylindrical member from outside through the outer pipe of the stuffer nozzle in synchronism with a timing that the squeezing rollers are separated from the cylindrical member.