PURPOSE: To permit the replacement of a hearth electrode in a very short time with easy work by a method wherein a lower furnace body is connected detachably to an upper furnace body and the upper furnace body is supported by an inclining and supporting mechanism while the lower furnace body is provided with a tap hole and the hearth electrode.

CONSTITUTION: A furnace body 2 is constituted of an upper furnace body 4 and a lower furnace body 5 while the latter is integrated detachably with the former by a coupling means 6. The present furnace is provided with an inclining and supporting mechanism 7, supporting the furnace body 2 inclinably, and a supporting device 8 for removing the lower furnace body 5. The lower furnace body 5 is provided with a tap hole on one part of the side wall and a tapping trough 17 is provided continuously to the tap hole. A hearth electrode is provided on the bottom of the furnace.