To provide a biometric authentication device which provides improved security level in authentication process.

A biometric authentication device includes: a memory unit 13 for storing registered biometric information 32, a biometric information classification code 31, and sample biometric information 33; a biometric information classification code producing unit 15 which compares authentication format biometric information 51 with multiple pieces of sample biometric information 33 to calculate degree of similarity respectively and produces a biometric information classification code 31 on the basis of the similarity; an authentication priority information producing unit 16 which assigns a priority to the biometric information classification code 31 of each piece of sample biometric information 33 in descending order of similarity between the authentication format biometric information 51 and the sample biometric information 33 on the basis of the similarity, and produces authentication priority information such that the registered biometric information 32 belonging to a group of biometric information classification codes 31 having a lower priority is not used as an authentication subject, on the basis of a prescribed threshold value; and an authentication processing unit 17.