During normal and reverse swings of a transducer main body, an engagement accuracy is ensured to reduce generation of vibration and noise. An ultrasonic transducer includes: a coupling 2 swingably and loosely fitted between one end portion of an output shaft 1a of a power source 1 that swings the transducer main body and the transducer main body, and a flywheel 3 swingably and loosely fitted to another end portion of an output shaft 1b of the power source 1, ensuring the reduced vibration and noise from the transducer main body.
