To prevent the increase of the diameter of a leading part by attaching a freely rotatable ultrasonic wave reception transducer composed of a piezoelectric element through a bend part on the tip side of the leading part composed of a flexible hollow member and installing an operation part for bending the bend part and a rotational drive control means on a base end side.

A driving means 24 composed of first and second piezoelectric elements is installed inside a tip part 14 formed on the tip side of the leading part of this ultrasonic probe 11 and a transducer 18 fitted inside the tip part 14 is rotationally driven. For the driving means 24 for electrically performing drive control, the insertion of a signal line 29 for impressing driving signals to the piezoelectric element in the leading part 12 is sufficient and the need of inserting a wire or a flexible shaft like the conventional one for mechanically performing rotational drive is eliminated. Since the diameter of the signal line 29 is smaller than the flexible shaft of the wire, the diameter of the leading part 12 can be made smaller for that portion. Thus, at the time of diagnoses, pains given to an examinee for whom the ultrasonic probe 11 is inserted into a celom are reduced.