Micro electrical discharge machining (EDM) and micro electrochemical machining (ECM) were studied for the fabrication of micro structures. Micro EDM has been used to machine micro structures from metals. However, since the tool wear is inevitable during the machining, the tool wear is drawback for the precision machining. Micro ECM is also used for micro machining and produces better surface quality than that of micro EDM. Moreover, since tool electrodes are not worn out, micro ECM is suitable for the precision micro machining. However, the machining rate is lower than that of micro EDM. In this paper, therefore, the hybrid machining process which uses micro EDM as roughing and micro ECM as finishing is introduced. By using this hybrid machining, a hemisphere with 100㎛ radius was fabricated and the efficiency of the process was investigated experimentally.
