PURPOSE: To provide an ultrasonic image of the front from the insert position of an oscillator with a conventional diameter.

CONSTITUTION: An ultrasonic probe 10 for internal body cavities has an oscillator 12 for transmitting and receiving ultrasonic waves provided on the probe top end part, and an oscillator holder 13 for holding the oscillator 12, and the oscillator holder 13 is connected to a shaft 14 for transmitting the rotation from a control part (rotated in the direction of a blanked arrow 100). The oscillator 12, the oscillator holder 13 and the shaft 14 are housed in a flexible tube 15 used also as an acoustic membrane, and the tube 15 is filled with water. A deflecting member 16 for deflecting the ultrasonic transmitted and received wave 200 of the oscillator 12 is provided on the upper surface of the oscillator 12. The material of the deflecting member 16 is a material in which the sound speed passing therein is higher than the sound speed passing in water and human body, and the upper surface is formed into a tapered form raised from the inserting direction to the rear.