PURPOSE: To retrieve information regardless of the type of numerics included in the registered retrieving information, by performing conversion between the numerics included in the registered retrieving information and those included in the retrieving information to be retrieved with the unified type of characters.

CONSTITUTION: In a retrieving mode the retrieving information is supplied in HIRAGANA (cursive form of Japanese syllabary) through an input part 1. Then the input retrieving information is converted into KANJI (Chinese characters) codes by a KANA (Japanese syllabary)/KANJI converting part 2 and stored temporarily in a KANJI code memory 3. Then the numerics of KANJI codes, i.e., the retrieving information read out of an external memory device 5 via a registering/retrieving part 4 are converted into KANJI codes of the prescribed character types by a numeric detecting/converting part 6. At the same time, the numerics of the KANJI codes stored in a KANJI code memory 3 are converted into KANJI codes of the character types similar to said ones by the part 6. Then both KANJI codes are compared with each other by a comparison part 7. When coincidence is obtained between both KANJI codes, the KANJI codes serving as the retrieving information are outputted from the part 4 and displayed on a CRT display 10.