After executing a second transmission (S2) constituting an ultrasonic wave of an amount of one frame from an ultrasonic wave having a high sound pressure of destructing bubbles of a contrast medium present in a predetermined section for making a blood stream image or a tissue image in a circulation image of a blood stream disappear by making the bubbles of the contrast medium present in the predetermined section disappear, there is carried out a third transmission (S6) by an ultrasonic wave having a low sound pressure of not substantially destructing the bubbles of the contrast medium for acquiring the circulation image of the blood stream with regard to the predetermined section. The first transmission (S4) is executed by the ultrasonic wave for making a portion of the blood stream image in the circulation image disappear by making the bubbles of the contrast medium at the predetermined region present in the predetermined section disappear as necessary while executing the third transmission. <；IMAGE>；
