An electrode tool for electrochemical machining includes a machining electrode surface (la) . The machining electrode surface (la) includes a conductive pattern defined by lands (3) and grooves (3a) that are formed by groove machining the electrode surface (la) . The machining electrode surface (la) is then molded with a hard insulating resin layer (4), and a surface of the hard insulating resin layer (4) is mechanically polished to expose the lands (3) of the conductive pattern. The lands (3) are chemically dissolved to obtain a conductive pattern (14) having a surface that is formed below a resulting insulating resin surface (2), with the height difference between the two surfaces being between 1 and 5 µm. The electrode tool allows precise surface machining of work pieces and can withstand prolonged use.