PURPOSE: To smoothly execute supply of a can to a lifter by executing the closing in a chamber in a condition by the contact with a can laying surface due to lowering the chamber.

CONSTITUTION: By shrinking a rod 17a in each chamber slide cylinder 17, the chamber 10 is lowered and the lower end thereof comes into contact with the can laying surface 19, and the inside of the chamber 10 is made to the closed condition. In this condition, vacuum treatment in the chamber 10 is executed in two stops of low vacuum and high vacuum. At the time of opening a supplying control value 21a in a gas supplying pipe, gaseous nitrogen is drawn in the chamber 10 and filled up into the can, too. When the lifter 52 ascends in this condition, a can cover is in pressurized-contact with a rotating chuck 24 and the can is rotated together with the lifter 52. By this method, flatness of shifting face from a belt conveyor 51 to the lifter 52 is secured and supply of the can to the lifter 52 can be smoothly executed.