A personal authentication system of this invention has a card reader, in which a bar code reading device for reading a two-dimensional barcode containing personal data, a CMOS image sensor for producing face data by photographing the face of a person, and a fingerprint reading device for producing fingerprint data by reading the fingerprint of the person are assembled as one unit. A personal computer performs a projection transform and a brightness correction to the barcode read by the card reader for acquiring accurate data. Then, the personal data, the face data, and the fingerprint data are compared with database for authenticating the person. Therefore, this invention achieves more accurate personal authentication and leads to improved security.