Provided is a compact ultrasound diagnostic device having a high degree of freedom in a viewing position and a viewing angle of a display panel and having excellent operability. The ultrasonic diagnostic device includes a main body (10) that includes an operation panel (20)； a first display (30) connected to the main body through a supporter (60)； and a second display (40) detachably connected to the main body. The second display (40) includes a transmission/reception circuit that performs transmission or reception with the main body (10). When the sub display 40 is detached, a connection unit (25) on a side of the main body, to which the sub display 40 is connected, functions as a connection unit of the main display 30.
