To improve an input environment by reducing too many keys of a keyboard, and to allow even an amateur to easily and surely input data without looking at a key screen.

The input of data except numeric values is operated by the combination of two digit numbers ranging from 1 to 9. The group of keys 1, 2, 3, 4 and 5 and the group of keys 6, 7, 8, 9 and 0 are divisionally arranged on the right and left parts of a display screen so that data can be inputted with right and left fingers. Substantially, a user can input data without looking at a key surface by allowing the fingers of his both hands to memorize the 9 keys. The larger number of inputs than a conventional manner can be ensured with the number of keys shown in this figure, and it is possible to facilitate a countermeasure to any language with software.