Abstract: An ultrasonic continuous wave doppler blood flow-meter deflects an ultrasonic continuous wave to an arbitrary angle and transmits it into an organism, thereby measuring a blood flow speed of the organism. Two continuous sine wave signals of different phases and a plurality of sets of pairs of coefficients are generated. One of each of the pairs of coefficients is multiplied to one of the two sine wave signals. The other one of each of the pairs of coefficients is multiplied to the other one of the two sine wave coefficients. After that, two sine wave signals after the multiplication are added, so that a plurality of synthesis sine wave signals are generated. When a plurality of micro vibrators are driven by the plurality of synthesis sine wave signals, the ultrasonic continuous wave is deflected to an arbitrary angle and is transmitted into the organism.