Abstract: The electrode length in an electric furnace is measured by arranging a wire conductor to depend right above a hollow electrode such that it can be lowered and raised through the hollow electrode. When the wire conductor is lowered through the hollow electrode and brought into contact with the molten process material within the electric furnace, an electric circuit constituted by the wire conductor, the process material and a power supply is closed so as to determine the electrode length extending below an electrode holder from a certain relation between the distance of descent of the wire conductor as indicated by a measuring means in accordance with current caused in the electric circuit upon closure thereof and a previously measured distance between the initial position of the end of the wire conductor before the descent thereof and the position of the electric holder.