PURPOSE: To shorten a molten metal supplying time by stopping the stationary ladle in the tilting posture when the molten metal does not flow-out into a triangle ladle, and starting the molten metal supplying from the tilting posture next time, in the case of supplying the molten metal by tilting the stationary ladle.

CONSTITUTION: The stationary ladle 2 is tilted at a high speed till detecting the molten metal 3 allowed to flow out from the stationary ladle 2 into the triangle ladle 1 with a phototube 4. The stationary ladle 2 is tilted at a low speed until the molten metal 3 reaches a level a little lower than the aimed level in the triangle ladle 1. At the time of detecting the molten metal 3 with a camera for picture processing, the stationary ladle is tilted so as to return back. In the case of detecting no molten metal allowed to flow out from the stationary ladle 2 into the triangle ladle 1 with the phototube 4, the stationary ladle stops the tilting for return-back. The supply of the molten metal 3 next time is started from the tilting posture of the stationary ladle 2. By this method, the time T1 required for the tilting for return-back and the time T2 for the tilting at the high speed can be shortened, and the number of times of the supplies of the molten metal 3 is increased and the casting efficiency is improved.