To provide an authority determination system, capable of preventing spoofing by a third person who has illicitly acquired an identification medium.

The authority determination system for performing authority determination for permission/prohibition of entrance to a plurality of small sections constituting a management area includes an identification information acquisition unit which acquires identification information stored in the identification medium carried by a user; a biological information acquisition unit which acquires biological information of the user; and a processing unit which performs entrance permission/prohibition determination by authentication of the identification information and the biological information to the user who enters the management area from the outside, and performs entrance permission/prohibition determination by authentication of the identification information to the user who enters each small section within the management area.