PURPOSE: To obtain an ingot or billet having the fine crystal grains of the solidified structure with a simple installation by cooling molten metal flow and adjusting the pouring rate thereof in the stage of pouring the molten metal which is heated in a vessel and is held at a prescribed temp. via a nozzle into a casting mold.

CONSTITUTION: Electric power is supplied to a heater 21 to heat the molten metal 11 in a tundish 12, etc. so that the molten metal 11 is held at the temp. within the range of the m.p. of the metal or alloy of the compsn. thereof W m.p.+15°C. Such molten metal 11 is poured through a nozzle 13 provided in the lower part of the tundish 12 (or on the side thereof) into the casting mold 15. Electric power is supplied to a coil 22 to heat the molten metal flow 14 passing through the nozzle 13 by a high frequency by which the solidification of the flow 14 in the nozzle 13 is prevented. A stopper 16 is vertically moved to adjust the supply rate of the flow 14 into the mold 15 so as to attain 1.0W5.0 cm/min rising speed of the molten metal level in the mold. Ar or the like ejected from gas ejection nozzles 20 is injected to the flow 14 by which the molten metal is cooled to a semi-molten state. The semi-molten metal 18 is cooled and solidified in the mold 15 and the ingot 19 is thus obtd.