An ultrasound diagnostic apparatus (1) includes a urinary bladder extraction unit (9), a feature quantity calculation unit (10), a candidate frame extraction unit (11), and a urine volume measurement unit (13). The urinary bladder extraction unit (9) extracts a urinary bladder region from ultrasound images of a plurality of frames. The feature quantity calculation unit (10) calculates a feature quantity related to the bladder region. The candidate frame extraction unit (11) extracts, from the ultrasound images of the plurality of frames, an ultrasound image of a frame for which the feature quantity becomes a local maximum, as an ultrasound image of at least one candidate frame that serves as a candidate subjected to measurement. The urine volume measurement unit (13) analyzes an ultrasound image of a measurement frame selected from the ultrasound image of the at least one candidate frame to measure a urine volume.