To realize a simple device for authenticating an individual which is not large-scale, uses auditory organs which any person has, and enables individual authentication that is hardly forged, hardly affected by health condition or secular change and causes little physiological adverse reaction, and to provide a method for authenticating individual.

The device has a sound receiving and originating part 11 (15), a signal processing part 14 for performing the signal processing of information on sound to be received and originated, a storage part 18 for storing the acoustic characteristic information of the auditory organs in advance and a signal processing part 14 which controls receiving and originating of sound and performs storing, comparing and discriminating of the acoustic characteristic information. By comparing the acoustic characteristic information of the auditory organs collected in advance with that measured as for a person to be authenticated, it is judged whether the person to be authenticated is the objective person of authentication.