A method and device for electrolyti

A method and device for electrolytic composite polishing to mirror-polish the inner surface of a long metal pipe. A plurality of rows of pieces of abrasive cloth whose grain sizes are different are arranged on the outer circumferential surface of a tool electrode attached to the tip of a rotary shaft with pressing plate springs between the cloth and electrode. The tool electrode is inserted into a long metal pipe and an electrolyte is injected into the pipe from the top of the pipe. The long metal pipe used as an anode is rotated at a low speed and the tool electrode used as a cathode is moved and drawn out of the bottom of the pipe while the tool electrode is rotating at a high speed by the rotary shaft to carry out the polishing from the rough polishing step to the finish step in one path. A rough polishing cloth, a medium polishing cloth and a finish polishing cloth which have different grain sizes are arranged in this order on the tool electrode along the axis of the tool electrode. The pressing force given by the plate springs is controlled by changing the number of plate springs. Thus it has become possible to protect the plate springs which press the polishing cloths and to carry out rough polishing, medium polishing and finish polishing in one path.