PURPOSE: To prevent uneven casting and to maintain uniform quality by inserting a molten metal conduit into a holding chamber formed of a refractory heat insulating material and providing a progressive magnetic field generator and heater along said conduit thereby preventing the solidification of the molten metal in the conduit and tapping the molten metal without temp. decrease.

CONSTITUTION: Electric power is always supplied to a hesting element 22 to maintain a high temp. in the holding chamber 21 and to heat a molten metal conduit 5 while the molten metal 3 exists in the conduit hole 5a of the pipe 5. The temp. decrease of the molten metal 3 in the hole 5a is therefore prevented and the molten metal 3 does not solidify in the hole 5a even during the halt of pouring. A coil 15 is excited by a prescribed phase difference to generate a progressive magnetic field in the hole 5 and to rise the molten metal 3 in the stage of pouring. Since the conduit 5 is kept heated, the temp. decrease of the molten metal 3 and the consequent uneven casting are obviated.