According to the present invention, a method of biometric authentication comprises, storing information corresponding to a plurality of users in association with first reference biometric data and second reference biometric data, the users being divided into first and second groups, the quality of the first reference biometric data of each of the users in the first group being not less than a predetermined level, the quality of the first reference biometric data of each of the users in the second group being less than the predetermined level, obtaining first biometric data of a user by inputting first biometric information of the user, providing first authentication, obtaining second biometric data of a user by inputting second biometric information of the user when the first authentication indicates presumed matching of the first biometric data with the first biometric reference data of one of the users in the second group and providing second authentication. The present invention achieving high-speed and high-compatibility rate biometric authentication, even if the user is incompatible with the high-speed authentication method.