PURPOSE: To house and transfer a molten steel in a nonoxidation state by mounting a sealing cap on a ladle, moving the cap toward the position below a converter, discharging the molten steel into the ladle through the molten steel flow sealing cylinder of the sealing cap and transferring the ladle after the sealing cap is removed and a hermetic cap is mounted.

CONSTITUTION: The sealing cap 5 suspended to a rod 9 of a seal attaching/ detaching mechanism 7 is mounted on the ladle b. A ladle truck 18 is moved to position the ladle 6 to the position below the converter 1. A part of a converter body side wall 1a of the tap hole 11 of the converter 1 is then brought into contact with the aperture end of the molten steel sealing cylinder 12 of the sealing cap 5. The molten steel in the converter 1 is discharged from the tap hole 11 through the molten steel flow sealing cylinder 12 of the sealing cap into the ladle 6 in the nonoxidation state. The ladle 6 is returned to the position of the seal attaching/detaching mechanism 7 and the sealing cap 5 is removed. The hermetic cap 19 is mounted on the ladle 6 and the ladle 6 is transferred to the ensuing stage.