PURPOSE: To attain high yield manufacturing of an ultrasonic probe for transmitting/receiving ultrasonic waves with high frequency by using a piezo-electric oscillator having high resonance frequency.

CONSTITUTION: The piezo-electric oscillator 2 having resonance frequency lower than objective resonance frequency is stuck to a damper 5 and the surface grinding work of the oscillator 2 is executed until the thickness of the oscillator 2 expresses the objective resonance frequency. An electrode 3 consisting of a conductive material is formed on the working face and a front plate or an acoustic lens is fixed to the surface of the electrode 3.