The present invention provides an ultrasonic probe contains at least one reception preamplifier that is provided per transducer element and connected to the transducer at an input side thereof and to a cable at an output side thereof, a transmission bypass unit that is connected between the cable and the transducer, blocks off a reception signal and allows a transmission signal to pass therethrough, and a floating unit that is connected between a power supply terminal of the preamplifier and a driving power source and increases impedance thereof for a high-voltage transmission signal, whereby a bias potential of the preamplifier is electrically set to a floating state and returned to an original bias potential by a reception time.
