Abstract: Pressure resistant containers, each consisting of a pressure resistant box opened at the front surface thereof and a wall plate, are circulated along an endless track with the wall plates directed outward. The front and back surfaces of each wall plate are each provided with a clamp for supporting a soft pliable bag. The bag is fed to the clamp disposed outside the pressure resistant container, and the bag is clamped by the clamp. The mouth of the bag is then opened to fill the bag with an article. Subsequently, the wall plate is turned inside out to admit the bag in the pressure resistant container, and the bag is subjected to a vacuum in the pressure resistant container and the mouth of the bag is sealed.