To provide an electrochemical machining tool capable of carrying out radial dynamic pressure generating groove machining, axial dynamic pressure generating groove machining of a sleeve used for a fluid dynamic pressure bearing, especially for a spindle motor for a hard disc and deburring work of an oil reservoir of an inner peripheral surface by simultaneously or properly selecting them.

This electrochemical machining tool is constituted of an electrode body to simultaneously carry out one or two or more of the axial dynamic pressure generating groove machining to carry out at a predetermined position of an end surface of a sleeve, the radial dynamic pressure generating groove machining to carry out at a predetermined position of an inner peripheral surface of the sleeve and the machining deburring machining to carry out at the predetermined position of the inner peripheral surface of the sleeve and an insulating guide tool furnished with an electrolyte passage forming function and a positioning function of an electrode against the sleeve and forms a passage through which an electrolyte flows by pressurizing and making an end surface of the insulating guide tool adhere on a sleeve holding tool or on the end surface of the sleeve held by it, and the electrochemical machining method applies this electrochemical machining tool.