This rehabilitation device consists of a pneumatic cylinder, a footrest for placing a foot, a stopper part that physically suppresses excessive bottom dorsiflexion exceeding the set angle of the footrest, a calf placement holder, and a frame supporting them. The angle adjuster portrayed in the figure is rotatable by 20 deg. It has a structure that is useful either in a sitting posture or in a supine position. In the rehabilitation operation, the direct motion movement of the cylinder is switched to the rotational motion about the ankle position, producing a mechanism shown in Figure 3 that can train up to 20 deg of dorsiflexion and 45 deg of plantar flexion. This angle is the joint movement range established by the Japan Rehabilitation Medical Society.