In electrochemical micromachining technique using ultra short pulses, the pulse duration is the only effective control parameter of the machining resolution. Here, we added an adjustable resistance in the equivalent circuit of the electrochemical micromachining. The machining resolution depends on both the pulse duration and the adjustable resistance. So, the adjustable resistance can be taken as another control parameter for the machining resolution. As the adjustable resistance increases, the machining resolution can be improved. This technique was used for machining micro beams, and a good machining resolution was achieved. (c) 2017 The Electrochemical Society.