PURPOSE: To efficiently separate and remove the non-metallic inclusions in a molten steel by blowing Al2O3 particles together with an inert gas into the molten steel so that the non-metallic inclusions are adsorbed into the Al2O3 particles.

CONSTITUTION: A refractory lance 3 is immersed into the molten teel 2 i a ladle 1 and the Al2O3 particle having 1W5mm particle size are blown together with the inert gas 4 such as gaseous Ar or N2 into the molten steel 2 through the lance 3; at the same time the molten steel is stirred. The non-metallic inclusions in the molten steel 2 are adsorbed to the Al2O3 particles 3 and the particles 5 adsorbed the non-metallic inclusions float on the surface of the molten steel 2. The particles 5 are removed from the surface of the molten steel 2.