PURPOSE: To make possible the easy changeover from the continuous rolling to the blooming at facing the trouble of rolling work, and to prevent the production from declination, by installing the changeover table between the continuous casting machine and the rolling mill, at continuously rolling the cast billet sent from the continuous casting machine.

CONSTITUTION: When the biting trouble happens in the rooling mill 10-3, the material 3 laid across the continuous casting machine 11 and the rolling mill is split by the cutter 5. At the same time, the speed of rolling mills 10-1, 10-2, is increased and the operation is continued until the split material 3 passes over the changeover table 6. And the changeover table 6 is put down by the moment that the tip of material 3 being sent from the continuous casting machine 11 arrives at the roll 6-4 of th changeover table 6. Hereby, the next material to be sent from the continuous casting machine 11 passes under the former material on the mill side, and is sent to the split billet conveying table 7; and the rear end of the billet is cut by the cutter 5 for obtaining the billet of specified size. And the split billet is carried away outside by the tables 6, 7.