PURPOSE: To improve the convenience of use of the operator by providing a documentation device storing the correcting content of the operator to the result to Kana (Japanese syllabary)-Kanji (Chinese character) conversion.

CONSTITUTION: An input control section 2 recognizes types of input character strings and operation of control keys and extracts a Kana character string being conversion object. The extracted Kana character string is fed to a candidate extracting section 3 via a conversion control section 7, and a conversion candidate corresponding to the character string is extracted by referring to a conversion dictionary and stored once in a candidate word storage section 32. The 1st candidate of conversion candidate information is displayed on a CRT6 from an output control section 5 under the control of the conversion control section 7. Other conversion candidate is displayed and selected by allowing the operator to depress a control key. The corrected conversion information is stored additionally in a conversion dictionary storage section 34 of a management section 4, allowing to use it from the storage section 34 for preceding use.