To improve efficiency in diagnosis, a cross-sectional image of a subject is sequentially produced based on echo signals acquired by conducting a scan involving transmitting ultrasound to the subject and receiving ultrasound reflected from the subject. A region of interest is then defined in the cross-sectional image of the subject, and a TIC image representing an average brightness values of all pixels in the region of interest in the sequentially produced cross-sectional image of the subject is produced such that the TIC image corresponds to a time axis along which the echo signals are acquired. Moreover, a property-of-ultrasound image representing the property of the ultrasound sequentially transmitted to the region of interest is produced such that the property-of-ultrasound image corresponds to a time axis of the TIC image. The produced TIC image and property-of-ultrasound image are displayed on a screen next to each other such that their respective time axes correspond to each other.