PROBLEM TO BE SOLVED: To provide an ultrasonic probe which can reduce a noise component of an ultrasonic signal.SOLUTION: An ultrasonic probe includes: an ultrasonic searching unit 10a which has an ultrasonic vibrator 1 for making an ultrasonic wave incident or outgoing, an ultrasonic propagation part 4 with acoustic impedance close to piping material and for improving the propagation density of the ultrasonic wave, and a matching layer 3 for connecting the ultrasonic propagation part 4 and the ultrasonic vibrator 1； and an ultrasonic attenuation part 5 which is provided on the outer periphery of the ultrasonic propagation part 4. The ultrasonic propagation part 4 includes a conical taper part 14 whose cross sectional area on the matching layer 3 side becomes smaller toward a piping 7 side.
