PURPOSE: To alter the, character size and the type face of KANA(Japanese syllabary) in accordance with a character string and to alter them independent of the character string when KANA is inputted to the character string in a document and the character size and the type face in the inputted character string are altered.

CONSTITUTION: Character information, the character size and the type face and position information on the designated character string, which are inputted from a keyboard 1, are stored in respective storage parts 17 and 18. Information on KANA, the character size and the type face, which are inputted to character information of position information, are stored in a KANA data storage part 19. Furthermore, the attribute of priority whether the character size and the type face of KANA are previously set or whether they depend on the designated character string or not is stored in the KANA data storage part 19. The attribute stored in the KANA data storage part 19 can be altered as to the having set KANA character string, and the character size, the type face and the attribute of the KANA character in the KANA data storage part 19, which are set in the character string within the influence range of the format alteration at time of altering the format of character information, can collectively or independently be reset.