An object of the present invention is to provide an ultrasound diagnostic device being able to display an ultrasound image which is not limited to a region targeted for ultrasound emission. The ultrasound diagnostic device 10 is provided with an ultrasound probe 2 having an ultrasound emitting surface for emitting an ultrasound wave and receiving a reflected wave of the ultrasound wave, an ultrasound image generating means 6 for generating an ultrasound image by using an reflected echo signal based on the reflected wave, an ultrasound volume data generating means 9 for accumulating the ultrasound images to generate three-dimensional ultrasound volume data of a test object, a reference image generating means 12 for generating multiple reference images by using three-dimensional volume data and the ultrasound volume data, and a display means 15 for displaying the ultrasound image and the reference images.
