Where is a place to be assisted for the patients with congestive heart failure? It is contraction of myocardium. We do not need to exchange the whole hearts. We started the ARTIFICIAL MYOCARDIUM development project. In the first step, pneumatic drive type artificial myocardium was developed. Next, development of an implantable type device was started. The animal experiment which studies the direct ventricle supporting effect by this motor was conducted. Although cardiac assistance of the right ventricle was enough as a result of repeating an animal experiment, the left ventricle supporting effect was inadequate. By such reason, we planned the development of an electrohydraulic driving system with grass fiber belt for fixation. The drive system with which it equipped between ribs controls silicon oil in our plan. Energy is supplied by transcutaneous energy transmission system from the outside of the body. As the results, this device is easily attached to the ventricle and the left ventricle and the right ventricle were able to be assisted as a result of the animal experiment. The cardiac output increased and blood pressure rose in the time series data during artificial myocardium support. Since this device is not a pump, it does not have a valve and does not have the risk of a thrombus, either. Therefore, it is also possible to implant in prevention to a slight heart failure patient. It is expected that it becomes an important artificial organ with a big market.