In the present invention, an ultrasound observation apparatus includes an information reposition portion (37) the information reposition portion (37) is a storage portion for storing various state information in an endoscope processor (4) inputted from a keyboard (5) and is configured to include a memory controller (38) and a data memory portion (29). Moreover, the keyboard is configured to include a key matrix (50), a keyboard controller (51), an ultrasound key processing portion (52) and an endoscope key processing portion (53). This configuration allows the ultrasound observation apparatus to easily share various state information of a plurality of apparatuses making up the system.
