An ultrasonic diagnosis apparatus including an ultrasonic probe having plural vibrating elements whose electromechanical coupling coefficients vary in accordance with the magnitude of a bias voltage supplied from a bias voltage supply unit, an ultrasonic image constructing unit for constructing an ultrasonic image on the basis of a reflection echo signal received from the ultrasonic probe, and a display unit for displaying the ultrasonic image is equipped with a calculation unit for calculating the magnitude of the bias voltage with respect to a collapse voltage of the vibrating elements, a storage unit for storing the calculated magnitude of the bias voltage, and a control unit for making the bias voltage supply unit supply the bias voltage to the vibrating elements in accordance with the stored magnitude of the bias voltage.
