PURPOSE: To automatically, surely and easily supply molten metal with less energy consumption and small occupying space and to soak heat expansion by supplying the molten metal while moving the molten metal to molten metal storing part by syphon action of an inverse-U shape pipe provided between the front end part of a molten metal supplying part and the rear end part of the molten metal storing part according to molten metal pouring quantity.

CONSTITUTION: An inverse-U shape pipe device 14 is constituted of the inverse-U shape pipe 30 whose end parts are positioned at the lower part of a chamber A in a boxy chamber and at the lower part of a chamber B being the molten metal passage in a fixed trough for supplying the molten metal and an electromagnetic induction type heater for temp.-keeping and heating around the inverse- U shape pipe. The device 14 is fixed to the trough part 11, and integrally moved when the whole boxy body 2 moves with the heat expansion. In the heat insulating part of the trough for supplying the molten metal, the space 33 arranged around the inverse-U shape pipe 30 is served as a moving margin.