PURPOSE: To suppress a side lobe level in a short axis direction and further to facilitate manufacture concerning the manufacture of an ultrasonic probe and a composite piezoelectric oscillator used for the probe.

CONSTITUTION: This ultrasonic probe divides a composite piezoelectric oscillator board 1 in the shape of arrangement and scans ultrasonic beams in an arranging direction A, and the composite piezoelectric oscillator board 1 is formed by joining plural piezoelectric oscillator boards 2 in a thickness-wise direction B orthogonal to the arranging direction A. Then, the above-mentioned piezoelectric oscillator boards 2 are arranged so that radial sound pressure or electric/ mechanical converting efficiency can be high at the center and gradually lowered toward the edge.