PURPOSE: To cool efficiently an electrode having permeability and to stir forcibly a molten steel by providing said electrode in the required position of a vessel so that a gas for cooling the electrode is supplied through the inside of the electrode to the inside of the molten metal.

CONSTITUTION: A vessel for a molten metal is provided with an upper electrode 11 and a bottom electrode 8. Single-phase AC or DC current is passed between the electrode 11 and the electrode 8 to generate an arc 12, thereby heating and melting the molten metal 13 in the vessel. The electrode 8 is formed to have air permeability and a gas 11 for cooling the electrode passed through the electrode 8 to cool the same and is then introduced into the vessel so that the molten steel 13 is forcibly stirred.