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