To provide a rotary actuator of a simple structure, quick operation speed and high reliability.

This rotary actuator is provided with a hollow cylindrical frame 1, a rotary shaft 2 rotatably supported at a center part of the frame, and a shape memory alloy coil 5, and is provided with a flywheel 3 provided coaxially with the rotary shaft, a handle 4 provided on a position shifting from the axis of a rotary shaft at a side surface of the flywheel, at least three shape memory alloy coils 5 fixed to the handle at one end and fixed to the frame at the other end, and lead wire 6 applying voltage to the shape memory alloy coils. The handle is made revolve around the rotary shaft by switching energization to the shape memory alloy coils sequentially.