PURPOSE: To automatically give a header used in information retrieval.

CONSTITUTION: Character information on a business card read by a business card input part 11 is fetched as image data, and also, a character string for the image data of the character information is segmented at a character string segmenting part 13, and the presence/absence of feature required for the setting of the header for a segmented character string is extracted at a feature extraction part 14, and the optimum character string as the header is judged from the presence/absence of extracted feature by a judging part 15, and the character string Judged as the optimum header is stored in image memory 12, and the character string as the header stored in the image memory 12 is displayed on a display part 17 when the information retrieval is performed, which enables business card information to be easily retrieved.