An ultrasound diagnostic apparatus includes a probe 102 that transmits and receives ultrasound waves to/from a subject, transmitting means 120 for supplying a drive signal to the probe 102 for transmitting ultrasound waves, receiving means 122 for receiving and processing a signal output from the probe 102, a displacement calculating unit 105 for measuring displacement of a tissue according to an output signal from an ultrasound transmitting and receiving unit 103, a color DSC 108 for reconstructuring an elasticity image on the basis of the displacement of the tissue, and an image display 112 for displaying the elasticity image. Further, the ultrasound diagnostic apparatus includes setting means 113B for setting a displacement search direction that sets a search direction of the displacement to match a tissue displacement direction for displacing the tissue. The color DSC 108 constructures the elasticity image on the basis of the measurement value of the displacement search direction.