According to an aspect, a personal authentication system is configured to execute fingerprint authentication processing by collating a first fingerprint image registered at fingerprint registration with a second fingerprint image acquired at personal authentication. The personal authentication system includes: a detection device configured to detect a touch position on a sensor and fingerprint data; and a control device configured to generate the first fingerprint image based on fingerprint data acquired at the fingerprint registration, segment the first fingerprint image into a plurality of first segmented images, and register the first segmented images.