An ultrasound diagnostic apparatus includes: a probe that transmits and receives ultrasound； a signal analysis unit that, when the probe scans a cross section of elevation direction of a blood vessel using ultrasound, detects a center scan line echo signal having passed through a center of the blood vessel among a plurality of scan line echo signals in the cross section of elevation direction of the blood vessel received by the probe, based on a part of each of the plurality of scan line echo signals that has a relatively small amplitude that corresponds to a reflected wave from a part of the blood vessel where blood flows； and an IMT measurement unit that computes an IMT from the center scan line echo signal. With this configuration, it is possible to provide an ultrasound diagnostic apparatus capable of performing wide-range IMT measurements with few errors even when a blood vessel seen from a body surface is not linear.
