PROBLEM TO BE SOLVED: To prevent a reduction in a recognition rate of a finger vein authentication device caused by erroneous insertion of a finger by a user who is unfamiliar with the finger vein authentication device or by insertion of a false finger by a malicious user, at low costs.SOLUTION: A personal authentication device is provided with: an imaging section for imaging a finger vein image a light source for emitting transmission light of a finger an image arithmetic section for performing verification of the finger vein image a guide section for indicating an imaging position of the finger a detection section for detecting contact of the finger with the guide section a light source for emitting reflection light irradiating a ball side of the finger switch sections that are pressed down by a tip portion of the finger a light source for emitting transmission light transmitting through the tip portion of the finger a light receiving element for receiving the transmission light transmitting through the tip portion of the finger display means for displaying information for guiding a user to proper use of the personal authentication device means for switching between 1-N authentication that performs verification of all registered images as targets in response stability of authentication and 1-1 authentication that inputs an ID number for identifying a user himself or herself beforehand and performs verification of an only registered image corresponding to the ID number as a target and means for updating registered data.
