PURPOSE: To manufacture plural pieces of non-segregated steel ingots by installing perpendicularly a refractory partition plate to the center in a casting mold, pouring a molten metal into the mold from the bottom, allowing the molten metal to solidify in one way from the side faces in parallel with the partition plate and removing the steel ingot from the mold and bisecting the ingot.

CONSTITUTION: A heat resistant partition plate 5 having low heat conductivity and small heat capacity is installed perpendicularly at the center in a casting mold 3. A molten metal 6 is poured into the mold from the bottom and is allowed to solidify in one way from the bottom of the casting mold and the side faces in parallel with the plate 5 of the mold 3. The central segregation is confined only to the limited part in the upper part or riser part of the mold and the unidirectionally solidified and non-segregated steel ingot is obtd. A good result is obtd. by the above-mentioned method alone in the case of a broad casting mold but a better result is obtd. by providing a heat insulating material on the side face of the mold supporting the partition plate in the case of a narrow casting mold.