To select and decide the input keys by an extremely simple operations while looking at a CRT display part by arraying the input keys on the keyboard face of an input device corresponding to approximately the same positions as their selection areas.

The input device 1 has a keyboard face 1a of an approximately similar shape (e.g. a rectangular shape) to a CRT display part 11. The input keys 2a, 2b, 2c, 2d and 2e and a decision key 2f are arrayed on the face 1a corresponding to approximately the same positions as their selection areas respectively. The keys 2a to 2e includes the selection keys 2a to 2d which directly select their selection areas and a shift key 2e that shifts a pointer 13 in both vertical and horizontal directions at the part 11. Other keys shift the selection items on a window screen and include an item shift key 3a, an operation window switch key 3b, a window screen size change key 3c, etc.