This biometric signature system comprises: a biometric certificate storage module that stores a biometric certificate generated on the basis of a user's biometric information; a biometric information acquisition module that acquires new biometric information from the user; a biometric certificate generation module that generates a new biometric certificate on the basis of the new biometric information; a biometric signature generation module that assigns a biometric signature to the new biometric certificate on the basis of the new biometric information; a biometric signature verification module that verifies the biometric signature using the biometric certificate stored in the biometric certificate storage module; and a biometric certificate registration module that registers the new biometric certificate in the biometric certificate storage module if verification of the biometric signature was successful.