PURPOSE: To save the trouble of a reconversion operation caused by the error of a homonym by means of learning information and to improve the operability of a KANA (Japanese syllabary)-KANJI (Chinese character) operation in a character processor.

CONSTITUTION: A KANA character string inputted from an input part 1 is inputted to a KANA-KANJI conversion part 4. The KANA-KANJI conversion part 4 converts the character string into a character string where KANJI and KANA are mixed by using information on a word dictionary part 2 and a learning information part 5. A learning information update part 6 updates learning information on all the candidates of the homonym to information different from initial information in the learning information part when a homonym selection part 1-1 selects the candidate. A learning information judgement part 3 judges whether the candidate where learning information is initial information exists in the homonym candidates or not. When the learning information judgement part 3 judges that the candidate where learning information is initial information is included, the KANA-KANJI conversion part operates so as not to rearrange the homonym candidates by learning information.