An active vibration isolation system has been proposed which uses an active dynamic vibration absorber as a servo accelerometer in a low-frequency range and as a vibration control device in a high-frequency range. Complimentarily, it uses an air actuator as a control device in a low-frequency range and a low-cost MEMS accelerometer as a sensing device in a high-frequency range. The main aim of this research is to develop a high performance active vibration isolation system that is lower in cost than conventional active vibration system. It is experimentally demonstrated that the acceleration in a low frequency range is estimated from the control signal of the absorber and the vibration is actually attenuated by feeding back the estimated acceleration.