PURPOSE: To surely and easily supply molten metal under the energy conservation and space conservation mode without using driving power to the conveying of the molten metal by arranging a reverse U-shaped tube between the front end part in a molten metal supplying part and the rear end part in a molten metal storing part.

CONSTITUTION: The molten metal storing part 2 succeeding to the front end part of the molten metal supplying part 1 is arranged and the reverse U-shape tube is arranged between the front end part of a molten metal passage in the molten metal supplying part 1 and the rear end part of a molten metal passage in the molten metal storing part 2. A weir 48 arranging a passage 47 at the lower part is arranged near the front end part of the molten metal passage in the molten metal supplying part 1 and a valve device 49 so as to be freely opened/closed is arranged to the outlet part of this passage. A pressurized gas supplying device 53 is arranged by connecting with the upper part of the molten metal passage at the front end part from the weir in the molten metal supplying part 1, or a reduced pressure sucking device 37 is arranged in the molten metal storing part 2, and then, a molten metal discharging device 13 is arranged to the front end part of the molten metal storing part. A valve device is closed and the pressurized gas is supplied, and when the molten metal starts to shift through the U shape tube, the valve device is opened. By this method, even at the time of being the normal operation, the molten metal can surely and easily be shifted by siphon action.