For easy and accurate assembly of a motor actuator with improvement of quality and productivity, a motor accommodating hole (2) continuously having a pressure insertion hole (2a) and an insertion hole (2b), and a coupler (4) having terminals (5, 6) are integrally formed in a motor case (1), the insertion hole (2b) is open to face to an opening (1c) of the motor case (1), the terminals (5, 6) are arranged in parallel to a longitudinal axis (X-X) of the motor accommodating hole (2), flat base plates (7, 8) which are orthogonal to a longitudinal axis (Y-Y) of a motor (3) and have connection holes (7a, 8a) are arranged in an outer periphery (3a) of the motor (3), the terminals (5, 6) are inserted into the connection holes (7a, 8a) when inserting the motor (3) into the insertion hole (2b) and then the motor (3) is pressure-inserted fixedly to the pressure insertion hole (2a).
