In the present invention, an ultrasonic diagnostic device, which has as an object of measurement the heart or blood vessels of a subject, is provided with a controller which performs the following: transmission processing for transmitting ultrasonic waves to the subject that includes the object of measurement reception processing for generating reception signals on the basis of echo signals that are from the subject that includes the object of measurement and that are received by an ultrasonic probe setting a plurality of observation points at different depth positions in the depth direction which is the direction in which ultrasonic waves are transmitted to the subject acquiring, on the basis of the received signal, information related to positional change of a tissue of the subject in a prescribed period in each of the plurality of observation points selecting observation points, for setting measurement regions, from the plurality of observation points by using the information related to the positional change of the tissue in the prescribed period acquired in each of the plurality of observation points, and information related to characteristic positional changes in the object of measurement and setting, on the basis of the selected observation points, the measurement regions for performing prescribed measuring processing.La présente invention concerne un dispositif de diagnostic à ultrasons, dont lobjet de mesure est le cœur ou les vaisseaux sanguins dun sujet, doté dun dispositif de commande qui effectue les actions suivantes : un traitement démission permettant démettre des ondes ultrasonores vers le sujet qui comprend lobjet de mesure un traitement de réception permettant de générer des signaux de réception sur la base de signaux décho provenant du sujet qui comprend lobjet de mesure et reçus par une sonde ultrasonore la définition dune pluralité de points dobservation à des positions de profondeurs différentes dans la direction de profondeur qui est la dire
