An ultrasonic probe is provided that is capable of preventing the probe's position from being displaced due to wire slippage on a drive pulley and a swing pulley while swinging. The ultrasonic probe includes an ultrasonic transducer unit emitting ultrasonic waves while swinging. Furthermore, a wire is attachable to the ultrasonic probe, which allows for the adjustment of a position angle of an ultrasonic transducer unit in swing operation without the use of a position angle sensor.