1. A method of certifying a user by using a learning system, the method comprising: if a reference image is registered, analyzing the reference image by using the learning system to detect characteristic information; storing the detected characteristic information; photographing a user to acquire a user image; analyzing the user image by using the learning system to detect face characteristic information and additional information of the user; comparing the face characteristic information and the additional information with stored characteristic information; and certifying the user based on a result of the comparing.