An inventive ultrasound diagnostic device is provided, which can display information on the temperature rise in a biological object under ultrasound radiation for measurement of a shear elasticity of a biological tissue of interest, thereby drawing attention of an examiner of the device and enabling him to retain the temperature rise within a predetermined safe range while performing the shear elasticity measurement. The device is adapted to measure the shear elasticity of a tissue by ultrasonic waves emitted from a probe. The device has a calculation unit configured to calculate a rise in temperature of the biological tissue irradiated with a focused ultrasonic (US) beam, and a display unit configured to display the temperature information obtained.