A face authentication system of an example of the present invention includes: a first face area detection unit configured to detect a first face image from a first captured image captured by a camera; a first deformation unit configured to deform the first face image non-linearly using a template face image; a face image recording unit configured to record the deformed first face image as a registered face image; a second face area detection unit configured to detect a second face image from a second captured image captured by a camera; a second deformation unit configured to deform the second face image non-linearly using the template face image; and a face image matching unit configured to compare the deformed second face image with the registered face image.