An ultrasound diagnostic apparatus equipped with: a probe position information-acquiring unit that acquires position information for a probe that acquires reception signals at various positions a feature extraction-computing unit that generates information for constructing three-dimensional images comprising the measured object based on the received signals with associated position information a feature data-comparing unit, which stores information acquired in the past for constructing three-dimensional images and position information for the measured object, the features of which were measured in the past, compares the information acquired in the past for constructing three-dimensional images with information acquired at the present time for constructing three-dimensional images, and reflects the position information for the measured object, the features of which were measured in the past, in the information acquired at the present time for constructing three-dimensional images and an image display processing unit that performs processing to display three-dimensional images based on the information acquired at the present time for constructing the three-dimensional images, the position information for the measured object, the features of which were measured in the past, that is reflected by the feature data-comparing unit, and the present probe position information.Linvention concerne un appareil de diagnostic à ultrasons comprenant : une unité dacquisition de linformation de la position de la sonde qui acquiert linformation de position pour une sonde qui acquiert des signaux de réception à différentes positions une unité de calcul dextraction des caractéristiques qui génère linformation pour la construction dimages tridimensionnelles comprenant lobjet mesuré sur base des signaux reçus avec linformation de position associée une unité de comparaison des données des caractéristiques, qui stocke linformation acquise dans le passé pour la construction dimages tridime
