PURPOSE: To keep a keyboard in a usable state at all times without any cable between a keyboard part and the body of the device by providing the keyboard part with a battery and automatically charging the keyboard when storing it in the body under the cableless condition.

CONSTITUTION: The keyboard part 1 transmits data to the body 11 by radio in accordance with the depression of the keyboard 2, and it consists of the keyboard 2, a keyboard controller 3, the battery 4, a terminal 5 and a transmission/reception part 6. Then, the keyboard part 1 is removed from the body 11 and power from the battery 4 is used in accordance with the depression of a key on the keyboard 2 in the keyboard part 1. Data is made into a code and is transmitted to the body 11 by radio. The main body receives it and executes a processing. When the keyboard part 1 is stored in the body 11, the terminal 5 of the keyboard part 1 is automatically brought into contact with the terminal 12 of the main body 11, and the battery 4 of the keyboard part 1 is automatically charged. Thus, the keyboard part 1 is always held in a driving possible state by the battery 4.