An electrolytic processing apparatus has at least one processing electrode (86) and at least feeding electrode (86) disposed on the same side as the processing electrode (86) with respect to a substrate (W). An organic compound having an ion exchange group is chemically bonded to at least one of a surface of the processing electrode (86) and a surface of the feeding electrode (86b) to form an ion exchanger (90). The electrolytic processing apparatus also has a substrate holder (42) for holding the substrate (W) and bringing the substrate (W) into contact with or close to the processing electrode (86). The electrolytic processing apparatus includes a power supply (48) for applying a voltage between the processing electrode (86) and the feeding electrode (86), and a fluid supply unit (92, 94) for supplying a fluid between the substrate (W) and the processing electrode (86).