There is provided an electrolytic processing apparatus and method that can effect processing of a substrate with high processing precision and can produce an intended form of processed substrate with high accuracy of form. The electrolytic processing apparatus includes: a holder (30) for holding a substrate (W); a processing electrode (32) that can come close to the substrate; a feeding electrode (34) for feeding electricity to the substrate; an ion exchanger (40) disposed in the space between the substrate and the processing electrode, or the substrate and the feeding electrode; a fluid supply section (70) for supplying a fluid into the space; a power source (68) for applying a voltage between the processing electrode and the feeding electrode; a drive sections (44, 56 and 60) for allowing the substrate and the processing electrode, facing each other, to make a relative movement; and a numerical controller (72) for effecting a numerical control of the drive sections. ATTACHMENT “B”