To simplify the configuration of electronic equipment using a keyboard by reducing the numbers of the scan lines and output terminals of the keyboard.

This keyboard 10 is provided with a plurality of key switches 11 which have an optional number of key contacts 12 which are respectively selected from a prescribed number of key contacts and a common key button and a prescribed number of scan lines 13 provided in accordance with the prescribed number of key contacts 12. Code signals being different in each key switch are outputted to scan line circuits 15 by respectively connecting the key contacts 12 in each key switch 11 with corresponding scan lines 13 in each key switch.