PURPOSE: To make the improvement of the separation efficiency of a solid foreign matter and an Al molten metal possible by rotating the Al molten metal and separating the solid foreign matter by a rotating magnetic field applied with a device disposed on the outer periphery of a hermetically sealed container.

CONSTITUTION: The Al molten which contains the solid foreign matters is poured from a pouring pipe 2 of a holding container 1 and the Al molten metal which has separated the solid foreign matters EM is withdrawn out of an withdrawal pipe 3. As a result, no vapor phase is present in the holding container 1. A rotating magnetic field-generating device 4 is arranged on the outer periphery of the hermetically sealed holding container 1 and the Al molten metal is rotated by the rotating magnetic field applied therewith, thus separating the Al or Al alloy molten metal and the solid foreign matters EM. Consequently, the clean Al molten metal or Al alloy molten metal is recovered without flowing out the separated solid foreign matters.