PURPOSE: To enhance damper effect, by forming a packing material for an ultrasonic probe from a composition prepared by containing at least some powdery materials having sound absorbing characteristics different in a particle size in a packing material.

CONSTITUTION: An ultrasonic probe 10 is constituted by providing an acoustic matching layer 3 to the front surface of a piezoelectric element 2 in order to efficiently emit an ultrasonic wave to a propagation medium. Further, an acoustic lens part 4 is provided to the front surface of said matching layer 3 in order to converge an ultrasonic wave and damping effect for suppressing vibration is imparted to the back surface of the piezoelectric element 1 and a packing material 5 for absorbing the emitted ultrasonic wave is provided. The packing material 5 is formed of silicone rubber filled with a large number of metal powders 6 different in a particle size and various frequency components are scattered by metal powders having diameters respectively corresponding to said components and energies thereof are absorbed and higher damping effect and sound absorbing effect are obtained.