A machining process based on Electro Discharge Machining (EDM) has been developed and allows producing flexible and low-cost tweezers-like grippers or grippers shaped for a specific application. It can be easily included in a micromanipulation setup and requires no additional hardware except the sparks generator: the machining is realized by the manipulator itself and due to this "in-situ" technique created grippers are exempt of misalignment errors. We have shown that precise micromachining of micro-parts or microstructures can be realized with a compact equipment. A microfactory concept has been introduced, in order to apply the "in-situ machining" technique to an automated and low cost clean-room manufacturing process. Issues for this application, particularly in term of contamination, have been discussed.