An ultrasonic probe having: an ultrasonic transmission and reception unit provided inside housing； and a drive device provided therein that encases a main sound transmission medium and swings the ultrasonic transmission and reception unit. The ultrasonic probe is characterized by: the drive device being a drive transmission mechanism that converts the rotation of a drive motor to swinging of the ultrasonic transmission and reception unit； all or part of the drive transmission mechanism comprising a gear mechanism； and preventing backlash in a meshing section of at least a pair of gears in the gear mechanism, by elastically impelling and pressing one pair of gears on to the other pair of gears by using compression springs.
