To dissolve the problem on shortage of heat, decarbonization or agitation in a specified area, by letting a fused metal electromagnetically flow from the vicinity of an arc spot to the heat-shortage area.

This DC arc furnace is provided with a furnace top preheating chamber 2, in the furnace body 1, and it is constituted such that it preheats a metallic scrap 3 by discharging exhaust gas through the preheating chamber 2, and that it can effectively utilize the heat of exhaust gas. DC power where a furnace bottom electrode 4 is a plus pole is applied between a furnace bottom electrode 4 and a bar-shaped electrode 5. Power supply lines 7 and 8 supply the furnace bottom electrode 4 and the bar-shaped electrode 5 with power. Then, by a large current being let flow, an arc 9 is generated at the tip of the bar-shaped electrode 5, and the fused metal 6 is heated. Accordingly, an upward current is generated in the fused metal 6. Therefore, the fused metal in the vicinity of the arc carries heat to the heat shortage area 13, which accelerates the fusion of the metallic scrap 3 dropped and cast in from the furnace top preheating chamber 2.