To enable a user to easily see necessary information in one screen by using the key pad separated from a screen display part and increasing the size of the screen display part at a maximum at user's request.

This device is constituted of the key pad 3 which is arranged below the front of a main body 1 and used to input necessary information and the screen display part 5 which is arranged above the front of the main body 1 and sends and displays a part touching it on a screen. In general cases wherein the screen display part 5 requires a small screen, the key pad 3 is inserted into a fixed piece and used in contact with the screen display part 5. When the screen display part 5 requires a large screen, the key pad 3 is separated from the fixed piece and puts away from the screen display part 5, so that the screen of the screen display part 5 can be expanded almost to the size of the key pad 3. Necessary information, messages, etc., can, therefore, be displayed over the entire screen of the screen display part 5.