To provide an operating method of an electric furnace having superior melting efficiency and electric power consumption rate.

A furnace profile 20 is created by connecting positions in a furnace body 4, of a predetermined temperature as a melting temperature of crust 8, a position of an electrode 5 in the furnace body is determined, and the positions of the furnace profile and the electrode in the furnace body are made visible. Raw materials are additionally charged into the furnace body, or operating conditions relating to the electrode are adjusted on the basis of a situation in the visible furnace. Troubles such as bridging can be prevented by adjusting the operating conditions.