PROBLEM TO BE SOLVED: To provide an ultrasonic diagnostic device provided with a tissue elasticity evaluation part with high reliability and an ultrasonic diagnostic method.SOLUTION: An ultrasonic diagnostic device includes a signal processing part 23 which transmits and receives an ultrasonic wave to a test object from a probe 11, and processes obtained reception data. A ROI (Region of Interest) detection part 21 of the processing part, on the basis of the luminance distribution of the reception data obtained by transmitting and receiving a first ultrasonic wave to/from the probe, obtains a distance index indicating a proper region for elasticity evaluation, installs a ROI on the basis of the value of the distance index, transmits a second ultrasonic wave to the ROI, and generates a shear wave. The elasticity evaluation part 22 calculates shear wave velocity with reception data obtained by transmitting and receiving a third ultrasonic wave, and outputs the shear wave velocity and the elasticity evaluation value of the ROI as a reliability index.
