An apparatus for authenticating a user includes a detector for determining a state or a position of a bodily part placed by the user for biometric authentication, a unit capable of obtaining biometric data from different portion of the bodily part, a plurality of biometric authentication engines capable of authenticating the user by using one of a plurality of authentication algorithms by comparing the biometric data with reference data, respectively, and a controller for selecting one of the different portions of the bodily part so as to select associated biometric data, and determining one of the biometric authentication engines for authenticating the user on the basis of the state or the position of the bodily part placed.
