An ultrasound transducer unit including a plurality of ultrasound transducers transmits and receives ultrasound waves to and from an inside of a subject. In a case where a checking operation unit is operated, a controller controls a driving voltage supply unit such that a driving voltage is supplied with all of the plurality of ultrasound transducers as driving target transducers. In a case where the checking operation unit is operated, a depolarization determination unit calculates, for each ultrasound transducer, a reception sensitivity in a case where an ultrasound wave is received by driving all of the plurality of ultrasound transducers as the driving target transducers, and determines whether or not a depolarization determination value calculated from the reception sensitivity of each ultrasound transducer satisfies numerical conditions. If the numerical conditions are satisfied, a polarization voltage supply unit supplies a polarization voltage to each of the plurality of ultrasound transducers.