Recently, electrical discharge machining (EDM) has been applied to micro processing. A thin electrode less than 0.1mm in diameter has been used for the micro EDM. In conventional micro EDM, minute energy is supplied to the gap region for micro removal machining. In this study, we carried out some experiments on single discharge machining with thin electrode. The value of discharge current was selected up to 50A as the machining condition. The electrode wear length was measured for several pulse durations. As a result, we found out the electrode became thinner than original diameters at the edge portion under pulse duration of several hundred μs in a single discharge. A needle of 35μm in diameter and 300μm length can be made instantaneously from a tungsten wire of 0.125mm in diameter. Using a thin electrode, micro drilling could be performed on the machine.