The present invention provides a personal authentication device or the like which imposes little psychological and/or physical burden on a user subject to authentication, and with which it is possible to easily ensure security. This personal authentication device 300 is provided with: a storage unit 37 that is capable of storing first identification information used for the identification of a user and second identification information used for, by a method other than said identification, consecutively identifying the user； an analysis unit 35 that analyzes information inputted to the user and generates the first identification information； a transmission unit 31 that transmits a first acoustic signal to a part of the user's head； an observation unit 32 that observes a second acoustic signal which is an acoustic signal resulting from the first acoustic signal propagating through said part of the user's head； a calculation unit 33 that calculates an acoustic feature from the first and second acoustic signals； an extraction unit 34 that extracts, from the acoustic feature, an acoustic feature quantity of the user as the second identification information； and a determination unit 36 that, in the case when the first identification information registered in the storage unit 37 has been verified to match the first identification information generated by the analysis unit 35, and at the same time, the second identification information registered in the storage unit 37 has been verified to match the second identification information extracted from the extraction unit 34, determines that the users are one and the same person.La présente invention concerne un dispositif d'authentification personnelle ou similaire qui impose peu de charge psychologique et/ou physique à un utilisateur soumis à une authentification, et avec lequel il est possible d'assurer facilement la sécurité. Ce dispositif d'authentification personnelle 300 comprend : une unité de stockage 37 qui est capable
