We have developed the shift lever with a spring connected link. It can detect the reaction force to the operator by using inexpensive displacement sensors such as potentiometers. For this system, we propose a model-based power assist control method. The proposed control system is composed of a reference generator and a feedback controller. The reference generator is introduced to generate an ideal reaction force to the operator. The feedback controller is designed by <i>H</i><sub>∞</sub> control theory to achieve disturbance attenuation. The effectiveness of the proposed method is shown by experiments.