A face authentication apparatus includes a face image acquisition unit that acquires a face image of a user who passes through a first gate provided at a first boundary between zones, a collation unit that performs face authentication on the face image on the basis of a threshold, an operating state acquisition unit that acquires an operating state of a second gate provided at a second boundary that is different from the first boundary, and a threshold change unit that changes the threshold on the basis of the operating state of the second gate.