A motor actuator includes a rotation sensor and a circuit board both of which are contained in a housing. The rotation sensor includes a rotation detection pattern for generating a detection signal indicating a rotational position of an output shaft, and an output terminal capable of outputting the detection signal from the rotation detection pattern. A terminal connection part to which the output terminal is connected is provided in the circuit board, and electronic components including a communication control unit for controlling the communications with an external control apparatus are mounted on the circuit board.