It is difficult to drive an actuator using muscular voltage measured by the conventional method, which is based on medical treatment and is not intended to elucidate the movement of an arm. In this paper, we propose a suitable measuring method to elucidate the movement by changing the position of an electrode. We also propose two evaluation values calculated from measured voltage to represent the movement of an arm. Using a fuzzy method based on these values, we can represent the movement of an arm fairly well. We applied this fuzzy method to driving an arm-type actuator, which can reproduce the movement of an arm.