A biometric authentication device, inputs biometric information such as a fingerprint, extracts feature information included in the biometric information, calculates the degree of reliability of the biometric information on the basis of the feature information, obtains a classification of the biometric information on the basis of the feature information, calculates the degree of reliability of the obtained classification, determines whether or not to execute an identification process between the input biometric information and biometric information enrolled in a storage unit on the basis of the degree of reliability of the biometric information and of classification, further determines whether or not a re-input process of the biometric information is needed, executes an identification process for the biometric information when it is determined that the identification process is needed, and issues a re-input instruction for the biometric information when it is determined that the re-input process is needed.