Provided is an ultrasound diagnostic device having an elasticity evaluation function with which high accuracy and high reproducibility can be achieved while avoiding the influence of internal stresses. The ultrasound diagnostic device comprises: a transceiver which causes a probe for transmitting and receiving ultrasonic waves to transmit and receive first, second, third ultrasonic waves to and from a subject； an image production unit for producing an image on the basis of a received signal related to the first ultrasonic wave； a velocity measurement unit which sets a measurement region on the basis of the produced image, transmits the second ultrasonic wave to the measurement region to create shear waves, and calculates the propagation velocity of the shear waves from a received signal obtained by transmitting and receiving the third ultrasonic wave to and from the measurement region； and an elasticity evaluation unit for evaluating the elasticity of the subject on the basis of the calculated propagation velocity. The velocity measurement unit measures the propagation velocity at the same position a plurality of times. The elasticity evaluation unit derives an elasticity evaluation index using variations in the results obtained by measuring the propagation velocity a plurality of times.
