1. A failure diagnosis method of an apparatus performing authentication by comparison of biometric data generated on the basis of biometric information of a user and reference biometric data of the user, the method comprising: outputting said reference biometric data on the apparatus; obtaining said reference biometric data outputted from the apparatus by a second apparatus; obtaining new biometric data on the basis of the biometric information of the user by the second apparatus; and performing authentication by comparison of said reference biometric data obtained by the second apparatus with the new biometric data to estimate the type of the failure of the apparatus.