[Problem] To select a period suitable for acquiring an elastic image in accordance with variation of the displacement amount of a moving tissue when the elastic image of the moving tissue is acquired, thereby stably acquiring an elastic image of high image quality.[Means for Resolution] A ultrasonic diagnostic apparatus including an ultrasonic probe for transmitting/receiving ultrasonic waves to/from a site containing a moving tissue of an examinee, ultrasonic wave transmitting means for outputting an ultrasonic wave signal for driving the ultrasonic probe, morphological image acquiring means for acquiring a morphological image representing morphological information of the site containing the moving tissue from a reflected echo signal received by the ultrasonic probe, elastic image acquiring means for acquiring an elastic image representing elastic information of the site containing the moving tissue by using a plurality of morphological image data, displacement amount detecting means for detecting a displacement amount of the moving tissue by using the morphological image data, and selecting means for selecting an elastic image acquiring period on the basis of the displacement amount, wherein the elastic image acquiring means acquires an elastic image during the selected period.
