Abstract: A method and apparatus for electrolytic treatment employing graphite electrodes wherein an asymmetrical waveform alternating current is applied to the electrodes to subject a metal web to a continuous electrolytic treatment. A graphite electrode in a treatment section is arranged confronting the metal web. Two graphite electrodes in current supply sections are arranged respectively upstream and downstream of the graphite electrode in the treatment section relative to a direction of movement of the metal web. Two auxiliary anode electrodes in the current supply sections are arranged respectively upstream and downstream of the two graphite electrodes in current supply sections. A part of an asymmetrical alternating waveform current is supplied to the auxiliary anode electrodes so that a current causing a cathode reaction on the surfaces of the graphite electrodes is made larger than a current causing an anode reaction thereon.