An authentication device (10; 20) that authenticates a user using person specifiable information, the authentication device comprising: a first storage unit configured to store person specifiable information specifying a registered user who is registered in advance; a second storage unit configured to store association information in which the registered user is associated with a predetermined terminal possessed by the registered user; a first acquisition unit configured to acquire person specifiable information from an authentication target user; a second acquisition unit configured to acquire identification information that is transmitted from a terminal present around the authentication device (10; 20); and a user specifying unit (15; 25) configured to specify a user associated with the terminal transmitting the identification information based on the association information and the identification information; characterized in that the authentication device (10; 20) further comprising: a determination unit configured to determine an order of comparison based on a result obtained from the user specifying unit specifying the user; and an authentication processing unit (16; 26) configured to authenticate the authentication target user by executing a comparison process between the person specifiable information of the authentication target user and the person specifiable information of the registered user stored in the first storage unit based on the order determined by the determination unit, wherein the authentication processing unit (16; 26) is configured to authenticate the authentication target user by executing the comparison process between the person specifiable information of the authentication target user and the person specifiable information of the registered user stored in the first storage unit in an order that is set by prioritizing the user specified by the user specifying unit (15; 25). a first storage unit configured to store person specifiable information specifying a registered user who is registered in advance; a second storage unit configured to store association information in which the registered user is associated with a predetermined terminal possessed by the registered user; a first acquisition unit configured to acquire person specifiable information from an authentication target user; a second acquisition unit configured to acquire identification information that is transmitted from a terminal present around the authentication device (10; 20); and a user specifying unit (15; 25) configured to specify a user associated with the terminal transmitting the identification information based on the association information and the identification information; characterized in that the authentication device (10; 20) further comprising: a determination unit configured to determine an order of comparison based on a result obtained from the user specifying unit specifying the user; and an authentication processing unit (16; 26) configured to authenticate the authentication target user by executing a comparison process between the person specifiable information of the authentication target user and the person specifiable information of the registered user stored in the first storage unit based on the order determined by the determination unit, wherein the authentication processing unit (16; 26) is configured to authenticate the authentication target user by executing the comparison process between the person specifiable information of the authentication target user and the person specifiable information of the registered user stored in the first storage unit in an order that is set by prioritizing the user specified by the user specifying unit (15; 25). a determination unit configured to determine an order of comparison based on a result obtained from the user specifying unit specifying the user; and an authentication processing unit (16; 26) configured to authenticate the authentication target user by executing a comparison process between the person specifiable information of the authentication target user and the person specifiable information of the registered user stored in the first storage unit based on the order determined by the determination unit, wherein the authentication processing unit (16; 26) is configured to authenticate the authentication target user by executing the comparison process between the person specifiable information of the authentication target user and the person specifiable information of the registered user stored in the first storage unit in an order that is set by prioritizing the user specified by the user specifying unit (15; 25).