Provided is an ultrasound diagnostic apparatus that measures an elastic modulus of a vascular wall, the apparatus allowing selection of a heartbeat suitable for the measurement of the elastic modulus. The problem is solved by storing M-mode images at predetermined intervals in the azimuth direction in a B-mode image, selecting a position in the azimuth direction in the B-mode image, and displaying the M-mode image of the selected position together with the B-mode image.
