The research aims to develop an experimental equipment to carry out in depth research on micro electrochemical machining (micro-ECM). The mechanisms of ultra-short pulse current micro ECM are discussed. As a consequence, lower machining voltage, lower passivity electrolyte concentration, high frequency short pulse power supply and micro rotating tool electrode at high speed have been synthetically used to localize the dissolution area during micro-ECM. The machining gap can be kept at a very small value, and the better resolution of machined shape is achieved by using a novel designed electrode gap control system and the effective utilization of ECM for micromachining is fulfilled. The experiments on microstructure by micro-ECM milling on stainless steel plate are conducted. The micro structures milled on 304 stainless steel foil with 300μm thickness with high precision and high aspect ratio are achieved, and the width of micro beam is about 60μm.