PURPOSE: To enable molten metal for continuous casting to be cooled safely and efficiently by allowing heat pipes sealed therein with a refrigerant to contact a mold directly or indirectly.

CONSTITUTION: Molten metal 6 come out from a heat insulating furnace is poured into a mold 5, and is cooled by a jacket 3 through the wall thereof, thence it is withdrawn as a cast ingot from the mold. Heat is successively transmitted from the molten metal 6 to the jacket 3 through the mold 5 and at the time when the refrigerant in heat pipes 1 evaporates, it deprives stopper plates 2 and the jackets 3 of heat, thereby cooling these. The refrigerant evaporated in the heat pipes 1 is water- or air-cooled by the projecting parts 1b of the pipes 1, whereby it is condensed. The condensate again returns to the jacket parts 1c, where it is evaporated. Since with this cooling device no water is directly flowed to the jackets 3, there is no danger for the explosion owing to the contact of the water and the molten metal and the device is safe. Also, cooling efficiency is high because the heat pipes 1 are used.