Provided is an ultrasonic diagnostic device that measures the modulus of elasticity of a vascular wall, said device allowing the selection of a heartbeat that is suitable for said measurement. Said problem is solved as follows: M-mode images are stored at prescribed intervals in the azimuth direction of a B-mode image, and in accordance with a selected position along said azimuth direction, the M-mode images at said position are displayed together with the B-mode image.
