The metal parts with small holes are widely used in the fields of aeronautics and astronautics. micro-electro chemical machining (micro-ECM) provides a viable alternative for drilling micro/small holes on metal parts with acceptable quality. This paper discusses the phenomenon of gas film formation of a certain insulation effects on the cathode, because of the cathode high speed rotating. Effects of several process factors, such as the cathode rotating speed on the radial of overcut, value of surface roughness and stray corrosion are investigated. The results show possibilities of improving the machining accuracy by utilizing cathode higher speed rotating.