The invention discloses an electric furnace. The electric furnace comprises a furnace lid (1) and a furnace shell (2), an entrance of the furnace shell (2) faces upwards, the furnace lid (1) is located above the furnace shell (2), and a high temperature resistance sealing ring (3) is arranged between the furnace lid (1) and the furnace shell (2). A water-cooled tube (6) capable of cooling the hightemperature resistance sealing ring (3) is arranged on the inner side of the high temperature resistance sealing ring (3), and the water-cooled tube (6) is arranged in the circumferential direction of the furnace shell (2). The electric furnace can achieve the sealing requirements in the furnace under certain conditions, thus reducing the amount of flue gas produced by the electric furnace, and thus reducing the load and energy consumption of electric furnace dust removal; the content of reducing gas in the flue gas is improved, and the further recovery and utilization of reducing gas produced in the furnace are facilitated; and nitrogen entering the furnace is reduced, the nitrogen content in molten steel is reduced, and the purity of molten steel is significantly improved.