In recent years, an apoplexy is many illnesses for Japanese people. If upper extremities become paralyzed by an apoplexy, the joints of them are transformed. The rehabilitation device is important and necessary for recovering a function of upper extremities. The purpose of my work is to develop a finger rehabilitation device using pneumatic soft actuators. This paper presents the structure and basic properties of a pneumatic soft actuator. We manufactured the bellows-shape actuator and the plane-shape actuator. It is seven types in all. The manufactured soft actuator has two internal chambers. When the pressure of one internal chamber is increased, the soft actuator bends in the direction opposite to the pressure-increased chamber. We have applied this operation to the finger rehabilitation device. Basic properties of the soft actuator are evaluated experimentally on the relationship between impression pressure and angle and the relationship between impression pressure and generative force. As a result, the maximum force of soft actuator has generated 3.19 N. The maximum displacement angle was 65 deg for the supplied air at 0.15 MPa. It shows that bellows-shape actuator is superior to the plane-shape actuator.