A control circuit of an ultrasound diagnostic apparatus having an ultrasound endoscope controls a transmission circuit to generate a transmission signal, which includes a diagnostic driving pulse applied to each of a plurality of ultrasound transducers that generate ultrasound waves for acquiring an ultrasound image, in the case of acquiring the ultrasound image, and controls the transmission circuit to generate a polarization driving pulse, which has a polarization driving voltage different from voltage of the diagnostic driving pulse within the same settable voltage range as the diagnostic driving pulse and has a frequency different from a probe frequency band for acquiring the ultrasound image, in order to perform the polarization processing of the plurality of ultrasound transducers in the case of performing the polarization processing.