An electrolytic processing apparatus which, while eliminating a CMP processing entirely or reducing a load on a CMP processing to the least possible extent, can process and flatten a conductive material formed in the surface of a substrate, or can remove (clean) extraneous matter adhering to the surface of a workpiece such as a substrate. The present invention includes an electrode section including a plurality of electrode members disposed in parallel, each electrode member including an electrode and an ion exchanger covering the surface of the electrode, a holder for holding a workpiece, which is capable of bringing the workpiece close to or into contact with the ion exchanger of the electrode member, and a power source to be connected to the electrode of each electrode member of the electrode section. The ion exchanger of the electrode member includes an ion exchanger having an excellent surface smoothness and an ion exchanger having a large ion exchange capacity.