Abstract text

An ultrasonic actuator (2) includes an actuator body (4) which performs a longitudinal vibration and a bending vibration, and a driver element (8a, 8b) which is provided on one of side surfaces of the actuator body (4) which is a mounting surface (40a), and performs an orbital motion in accordance with the vibrations of the actuator body (4) to output a driving force. The driver element (8a, 8b) includes a first driver element (8a) and a second driver element (8b) which are provided on the mounting surface (40a) at different positions in a longitudinal direction of the actuator body (4). The first driver element (8a) and the second driver element (8b) are located at different positions in a thickness direction of the actuator body (4).