PURPOSE: To perform highly accurate finish work through simple structure, by pressure inserting a tool having a resilient liquid-pass member for supporting abrasive grains on the aoutercircumference into a cylinder and performing electrolytic abrasive grain polishing.

CONSTITUTION: A resilient liquid-pass member 5 is wound and fixed over the outercircumference of a conductive rotary support 4 to support the abrasive grains. Then said tool is pressure inserted into a work or a cylinder 1 and electrolyte is fed to the working section to perform complex working of electrolytic working and abrasive grain polishing while rotating, reciprocating the tool. NaNO3, KNO3, etc. where passive state film is easily formed are preferable as the electrolyte.