PURPOSE: To ladle molten metal at an appropriate temperature immediately after charging a solid material into the molten metal in a melting furnace.

CONSTITUTION: A melting furnace 1 is provided with a crucible 2, a cover 3 for covering the crucible 2, and a cylindrical member 5 having a branching tube 4. The branching tube 4 branches slantingly downward from the upper part of the cylindrical member 5 and is so formed that a lower opening 14 of the branching tube 4 can be seen through an upper opening 9 of the cylindrical member 5. The cover 3 is provided with a non-combustible gas feed pipe 16a having an opening which opens to a space 15 of the melting furnace 1, while a large-diameter part 11 of the cylindrical member 5 is provided with a non-combustible gas feed pipe 16b having an opening which opens to a space 17 of the cylindrical member 5, and non-combustible gas is fed into the spaces 15, 17 from a bomb 19 through the non-combustible gas feed pipes 16a, 16b.