PURPOSE: To form a good clad ingot having an excellent binding state by drawing a base metal ingot while having an unsolidified state remaining on part of the surface, depositing a molten metal for a different cladding metal onto the unsolidified surface thereof and drawing the ingot while solidifying both metals.

CONSTITUTION: The molten metal A for the base matel is supplied from a tundish 1 into an uneven surface solidification tank 3 where the molten metal is stored. The molten metal is solidified from the part in contact with an uneven surface solidification device 5 and is drawn as the base metal ingot (a). The solidifying speed of the base matel is controlled in such a manner that the thickness in the solidified part of the base metal ingot (a) is not larger than the size of a drawing port 6. The base metal is heated during drawing so that the unsolidified state slightly remains on the top surface of the ingot (a) in contact with a solidification preventive device 7. The molten metal B for the cladding metal different from the base metal is then supplied from a tundish 2 into a deposition treatment area 8 where the said metal is deposited on the unsolidified surface of the ingot (a). The molten metal B for the cladding metal is drawn while said metal is solidified by a complementary solidification device 9 in common use for drawing and is cooled by the cooling water from coolant sprays 12, by which the clad ingot is formed.