An electrolytic apparatus that is used for a workpiece having an irregular cross-sectional shape, the workpiece having a hollow section that is formed vertically therethrough, and having a plurality of protrusions and a plurality of recesses that are formed on an inner surface thereof, the electrolytic apparatus includes a mounting section that closes a lower opening of the workpiece, a holding section that closes an upper opening of the workpiece, and an electrode that is placed inside the workpiece, the electrode having a hollow cross-sectional shape, and having a plurality of jet orifices for discharging an electrolyte solution respectively toward the plurality of recesses of the workpiece, and the mounting section and/or the holding section having a plurality of drain outlets that are provided respectively corresponding to the plurality of recesses of the workpiece.