PURPOSE: To display the KANJI (Chinese character) character information on a declensional KANA ending field simultaneously with KANA (Japanese syllabary) character information with a single KANA input operation by defining the coordination of the KANJI field and the declensional KANA ending field on a display device.

CONSTITUTION: A controller 1 is connected to a display 5 and a storage device 4 through a bus 2, and to the display 5, a keyboard 6 is connected through a bus 3. In such a state, KANA character information inputted by a KANA by the keyboard 6 is stored temporarily in a storage device 4, and also, subjected to KANA/KANJI conversion by the controller 1, and displayed on the display device 5. That is, when it is defined that a KANJI field and a declensional KANA ending field are a pair, KANA/KANJI conversion is executed by a first KANA input operation and the KANJI character information concerned is displayed in order to display the KANJI character information concerned in the KANJI field, and first inputted KANA character information is displayed on the declesional KANA ending field. In such a manner, the KANJI character information and the KANA character information can be displayed simultaneously by a single KANA input operation.