An authentication apparatus for authenticating using biometric information of a plurality of kinds including first information related to a first body part input into a first information inputting area and second information related to a second body part input into a second information inputting area includes an information existence detecting unit that detects a lack of the second information, a determination information acquiring unit that acquires information for lack determination based on third information related to the second body part input into the first information inputting area, and a pseudo lack determining unit that determines whether the lack is an actual lack or a pseudo lack based on the information for lack determination.
