A rubber artificial muscle has be feature of light weight and mechanical flexibility due to its own structure and air compressibility. Hence it may be suitable for a robot which has to safely operate for human. However, the air compressibility makes accurate control difficult. This study aims to clarify the fundamental control performances of a rubber artificial muscle actuator. Continuous path control, force control and compliance control are executed. A pressure control system is constructed to improve the pressure response. It is shown that satisfactory continuous path control can be accomplished by means of feedfoward compensation. Furthermore, it is confirmed that this actuator is useful for control of delicate force and high compliance.