A rotary actuator includes a PWB motor and a wave gear drive. The PWB motor is an axial gap motor. A motor rotor in the PWB motor includes a rotor disk coaxially affixed to a hollow motor shaft and a rotor magnet affixed to the rotor disk. A motor stator is composed of a printed wiring board, and includes an insulating substrate and a motor coil defined by printed wiring formed on the insulating substrate. Compared with a conventional rotary actuator using an SPM motor or the like, the shaft length can be shortened and the hollow diameter thereof can be increased.