To efficiently control plural medical instrument with simplicity and at a low cost by a single control panel.

This control panel 4 consists of a CPU 16 for detecting the key input of the key matrix 11 of a keyboard part 15 and driving of plural LEDs, a track ball controller part 17 for reading movement data in the track ball 13 of the part 15, an endoscope I/F part 18 for outputting information inputted by the part 15 from the CPU 16 to a cable for an endoscopes by an RS 232c, an ultrasonic I/F part 19 for outputting information inputted by the part 15 from the CPU 16 to an ultrasonic cable 9 by a PS/2, and a power source control part 20 having relays 20a and 20b for controlling a power source from an endoscope device 2 or an ultrasonic observing device 3 to be an internal power source.