PURPOSE: To obtain an ingot which is decreased in central segregation, center porosity and columnar crystal and has uniform characteristics by forming magnetic fields to an ingot part and supplying specific AC current to the ingot.

CONSTITUTION: A stirrer or permanent magnet 3 is installed between rollers 2 in a secondary cooling zone 1 of a continuous casting device so that the magnetic fields are generated in the ingot 4 which is in the process of solidification. Oscillating force 8 is generated in the direction perpendicular to the drawing direction as the AC current 5 of 100W1000Hz acts on the magnetic force 7 by the stirrer or permanent magnet 3 when the above-mentioned current is passed between the rollers 2-1 and 2-2. This vibrating force 8 is generated in the shell part where the AC current flows. The shell part is then oscillated and, therefore, the columnar resin-like crystal is broken. The ingot having the uniform characteristics is thereby obtd.