At least one wrong template for storing features of pattern information imaged on condition unsuitable for biometric authentication is provided and the wrong template information is collated with collation template information produced by extracting features from biometric information when authentication information is registered. When similarity is low, the collation template information is stored in an authentication template. The collation template is collated with the wrong template upon authentication and when similarity is high, authentication processing is not made. Further, when similarity of the collation template information and the wrong template information is high, a guidance message for solving a problem is displayed to the user. Thus, reduction of authentication performance is prevented.