<p>A composite machining device for reliably machining a conductive material such as a copper film with a low surface pressure and with a high rate while effectively preventing, e.g., a pit. The composite machining device comprises a machining table (46) composed of a substrate holder (42) for holding a substrate (W), a machining section (82) for machining the surface of the substrate by a machining method including a mechanical action, and an electrochemical machining section (84) that has a machining electrode (86) with an ion exchanger (92) and is adapted to machine the substrate (W) by applying a voltage between the machining electrode (86) and the substrate (W) after bringing the ion exchanger (92) into contact with the substrate (W); a liquid supply unit (94) for supplying liquid into the space between the substrate (W) and the machining electrode (86) and the space between the substrate (W) and the machining section (82); and a drive unit for relatively moving the substrate (W) and the machining table (46).</p>
