To enable continuous casting even in the case of using ladles different in size, without reconstructing an equipment such as existent ladle loading device.

The small size ladle 4 is turned with respect to a trunnion bearing of the large size ladle loading device 10 so that the position of nozzle hole 6 at the bottom part of the small size ladle 4 is made almost the same with the position of nozzle hole at the bottom part of the large size ladle in the horizontal direction at the time of loading the large size ladle. Further, the trunnion shaft 5 of the small size ladle 4 is supported at the position lower than that of the trunnion bearing of the large size ladle loading device so that the position of nozzle hole 6 at the bottom part of the small size ladle 4 is made almost the same with the position of nozzle hole at the bottom part of the large size ladle in the vertical direction at the time of loading the large size ladle.