An electrolytic processing apparatus can detect the end point of electrolytic processing stably with high precision and with a relatively simple construction. The electrolytic processing apparatus includes: a processing electrode which can come close to or into contact with a processing object; a feeding electrode for feeding electricity to the processing object; a fluid supply section for supplying fluid between the processing object and at least one of the processing electrode and the feeding electrode; a processing power source for applying a voltage between the processing electrode and the feeding electrode; a drive section for causing relative movement between the processing object and at least one of the processing electrode and the feeding electrode; and an eddy current sensor for detecting the thickness of the processing object from a change in eddy current loss. The sensor is disposed not in contact with (or separately) by an insulator from the processing electrode and/or the feeding electrode.