a biometric authentication device has high security by preventing intra - device information from being falsified and stolen by a third party . a biometric authentication device includes a biometric information storage module , a biometric information authenticating module for individual authentication , a mutual authentication module with the terminal , a registration counter corresponding to the mutual authentication , an authentication counter corresponding to the biometric authentication , a stoppage flag set when the value of the counter is larger than a predetermined value , and authentication control module for preventing the module from operating depending on the stoppage flag .