Heating in an electric furnace is made by electric energy. Raw ferrous materials consist mostly of scrap, some cold pig iron and DRI. For this reason, the electric furnace plays an important role in the recovery and recycling of waste iron resources. In areas where an abundant supply of scrap and electric power are available, the proportion of steelmaking via the electric furnace route is relatively high, because both energy consumption and equipment investment are substantially smaller than via the integrated route using a BF and BOF to produce steel from ore. Electric furnaces are classified as arc furnaces or induction furnaces, according to the heating method. The arc furnace is used far more extensively for steelmaking because its capacity is large and production efficiency is high. In addition to melting, both oxidation refining and reduction refining are possible in the arc furnace; the former is used for decarburization, dephosphorization, and dehydrogenation, and the latter for desulfurization and deoxidation. The arc furnace is also capable of melting a higher fraction of alloy scraps. For this reason, it is often used to refine high-alloy steels, such as stainless steel. However, with the introduction of secondary refining processes such as the argon oxygen decarburization (denoted AOD hereinafter) and vacuum oxygen decarburization (VOD) processes, which are exclusively used for refining stainless steel, the role of the arc furnace has been limited to high-efficiency melting in the upstream process. Even with commercial grades of carbon steel, it is common to conduct high-efficiency melting and decarburization in the arc furnace and to finish the process with a separate secondary refining furnace. The efficiency of heating, melting, and decarburization in the arc furnace has been substantially increased by adopting an ultra high-power transformer and oxy-fuel burner, as well as by injecting coal powder and pure oxygen gas. Cooling and protecting the furnace walls and ceiling with water-cooled panels has also been enhanced, enabling an increase in production efficiency from 80 to 120 ton/h. Recent trends have seen a shift from the alternating-current arc furnace to the direct-current arc furnace, the introduction of preheating and continuous charging equipment for scrap, and the adoption of the eccentric furnace-bottom tapping. The DC arc furnace offers lower unit consumption of power, electrodes, and refractories, and both noise and flicker are also lower. The preheating and continuous charging equipment for scrap decreases the energy consumption because preheating is carried out by the high-temperature exhaust gas, and heat loss by opening the furnace lid during conventional scrap charging can be prevented. The eccentric bottom-tapping allows efficient tapping without tilting the vessel, and is desirable for maintaining the cleanliness of the molten steel, because the carry over of oxidizing slag into the ladle during tapping can be prevented.