In this paper, a novel control index of the bilateral control for master-slave system with different motion areas is proposed. Most of applications of the bilateral control are composed of the master-slave system with same motion areas. For realizing master-slave system with different motion areas, micro-macro bilateral control and dimensional scaling bilateral control were proposed. In these methods, however, the conventional control index of the bilateral control "transparency" is not applied because of the different motion areas between the master and the slave. Therefore, the evaluation of these methods which consist on master-slave system with different motion areas have not been conducted. On the other hand, the proposed control index is based on the operational energy of the operator. By using the proposed control index, therefore, the superiority of the bilateral control is shown by the operational energy. In addition, this paper shows that the dimensional scaling bilateral control is superior to the micro-macro bilateral control from operational energetic point of view by the proposed control index. Finally, the validity of the proposal is verified by experimental results.