A Micro Wire Electrical Discharge Machining (MWEDM) prototype is developed for fabricating micro complex parts. It mainly includes granite basement, micro energy pulse generator, precise servo mechanics, detection and servo control system, constant tension winding systems. Experiments are done on the prototype. Experimental results show that: the peak current and pulse duration have obvious influence on surface roughness and machining time, and they also have an optimum value for the highest cutting speed. The servo reference voltage also influences the surface roughness and machining time. Utilizing micro wire electrode with diameter in 30m, the MWEDM can machine micro slot with minimum size of 38m, which proves that the discharge gap width can be controlled not more than 4um, and so small discharge gap is beneficial for part’s machining accuracy. All kinds of complex micro part (such as micro gear, micro bearing bracket, micro shaped holes, etc.) can also be machined by this prototype.