The purpose of this study is a development of a nonmetallic and light robot hand driven by low-pressure pneumatic actuators. As the robot hand is used pneumatic actuators, if a human touches the robot hand, it is safe. The results of characteristics of the pneumatic actuator proved that it is possible to drive the robot hand and get enough generated force to grasp objects by lower inner pressure and lower air volume. Therefore, a model the same size as a human hand can be made without a big air compressor, and applications for prosthetic hands are considered.