An ultrasonic diagnostic apparatus is disclosed for improving the signal to noise ratio of a receiving system, and allowing demodulation processing of ultrasonic reflection signals at the transducer during the receive process. The ultrasonic diagnostic apparatus includes an ultrasonic probe which transmits and receives ultrasound to and from a subject, a transmitting unit which supplies driving signals to the ultrasonic probe, and a receiving unit which processes signals to be output from the ultrasonic probe and calculates diagnostic information regarding the subject. The ultrasonic probe is equipped with a receiving transducer having sensitivity which changes according to the level of bias voltage to be applied. The receiving unit is equipped with a modulated bias amplification unit which applies signals of bias voltage with modulated amplitude to the receiving transducer.
