An electrochemical machining tool (3) includes a tool body (10) which has an electrode (11) which is made of a flexible conductive material having a cylindrical shape extending along an axis (O), and inside which an electrolyte (W) flows toward a leading end (10a) side, and an insulating layer (12) coated on an outer circumferential surface of the electrode (11) to expose a leading end surface of the electrode (11), wherein a non-insulation section (15) which exposes the outer circumferential surface of the electrode (11) is formed on the tool body (11), and the non-insulation section (15) is surrounded by the insulating layer (12) from an axial (O) direction.