This paper presents a control method for multi-degree of freedom system with an AMD (active mass damper). A sliding mode controller is applied to vibration control for a nonlinear model of five degree of freedom with an AMD. The output feedback control procedure has the switching hyperplane with dynamics by a liner operator. Therefore, the frequency shaping controller is introduced not only to suppress the chattering and the spillover, but also reduce the sensitivity of the motion of AMD to disturbance in extremely low frequency region. The effectiveness of the controller is demonstrated by the numerical results and the experimental ones.