PURPOSE: To perform the Kana-Kanji conversion input efficiently with a small- sized and light-weight device, by arranging the whole of keys including function keys in both sides of Kana character keys and making it possible that the operator turns the wrist of his hand put on a box body to input data with an input pen.

CONSTITUTION: A flat key cinstitution where an input port part 1 is provided on the same plane as the upper face of a box body 21 and has many input switch parts is given to the device, and switch parts are depressed with an input pen 35. Kana character keys 41 are arranged in the center of the port part 1, and function keys 48 and 49 and other keys are arranged in the left and the right of keys 41. The range in the lateral direction for the arrangement of the whole of keys including keys 41 is so set that the operator turns only his wrist to perform the input operation with the pen 35 without moving the position of his hand put on the box body 21. Thus, the whole of keys including keys 41 is arranged in this region.