An ultrasound diagnostic apparatus comprising: an image forming unit which forms an ultrasound image that corresponds to an echo signal received from a subject to which a contrast medium has been administered; a region of interest setting unit which sets, in a target region corresponding to target tissue on the ultrasound image formed by the image forming unit, a first region of interest and a second region of interest which are two regions different from each other; a feature value extraction unit which extracts, as a feature value, a difference in brightness between the first region of interest and the second region of interest set by the region of interest setting unit; and a type determination unit which determines, based on the feature value extracted by the feature value extraction unit, a type of the target tissue.