Abstract: A new type DC submerged-arc furnace with twin electrodes and oblate stack is introduced. The running characteristics are examined and the energy index of this furnace as well as the quality of MgO are investigated by comparing with AC submerged arc furnace performance. The results show that the main advantages of this furnace which use DC power and twin electrodes on current line are lower flicker effect, lower noise and steady operation state. The electric energy consumption of the DC furnace decreases and the electrode consumption is reduced by 50%. In addition, the oblate stack of the DC furnace is favorable MgO crystallization and the MgO yield with purity over 98% increase by 15%.