PURPOSE: To enable simultaneous or alternate display by expanding two magnified display parts or more on a screen where an overall image is displayed in the observation of the overall image.

CONSTITUTION: This apparatus displays an ultrasonic image built with an image processing section 4 on the screen of a display system 7 based on a received signal obtained by transmitting an ultrasonic wave to or receiving it from an object to be inspected. The apparatus includes a magnified display part specifying means 8 which can specify a plurality of magnified display parts simultaneously and properly in an overall image of the ultrasonic image and a display control means 9 which enlarges two magnified display parts or more selected from the plurality of magnified display parts as given by the magnified display part specifying means 8 on the screen of the display system 7 together with the overall image to perform simultaneous or alternate display.