To provide an electrode lifting device of an AC arc furnace which is capable of substantially reducing arc stops generated during an operation, shortening the operation time, and reducing a power cost.

This electrode lifting device includes an electrode 2 for generating arc between a scrap 4 and melting the scrap 4 inside a furnace body 3, an electric motor 5 for driving the electrode 2, and a controller 6 for controlling the electric motor 5. The controller 6 controls the electric motor 5 so that impedance between the electrode 2 and the scrap 4 is fixed at normal time. Also, when the length of the arc generated between the electrode 2 and the scrap 4 becomes a prescribed value or longer, the controller 6 cancels impedance fixing control and controls the electric motor 5 so as to lower the electrode 2.