Active microvibration control systems are becoming necessary in high-technology fields such as semiconductor manufacturing. In this study, an active 6 DOF microvibration control system using a giant magnetostrictive actuator was developed. The actuator consisted of a giant magnetostrictive rod of a 50mm length and a 6 mm diameter surrounded by a driving coil. A control law was adopted to provide almost the same performance as that of sky-hook systems by using only absolute acceleration, instead of achieving feedback of absolute displacement and velocity. Through vibration control experiments, it was shown that performance of the system was sufficient for implementation, including isolation performance against micro floor motion, damping performance against direct disturbance, and control system robustness.