To provide an ultrasonograph with which the change of an image caused by a contrast medium in an ultrasonic image and medical images other than the ultrasonic image of a subject to which the contrast medium has been administered can be suitably observed on one screen.

The ultrasonograph has a display image control part which displays a contrast image CG as the ultrasonic image UG of the subject to which the contrast medium has been administered, and displays an X-ray CT image XG as a medical image other than the ultrasonic image acquired beforehand about the subject to which the contrast medium has been administered. The display image control part displays the X-ray CT image XG of a time phase that corresponds to the contrast image CG about the same cross section.