An authentication server 2 of the present invention (i) communicates with a multifunction apparatus 1 including a web browser section 15 and (ii) carries out an authentication process for a user who operates the multifunction apparatus 1. The authentication server 2 includes: a user authentication section 25 for (i) obtaining, from the multifunction apparatus 1, login information entered in the multifunction apparatus 1 and (ii) carries out authentication for the user; a second communication section 20 for obtaining Cookie information from the web browser section 15 of the multifunction apparatus 1 with which the authentication of the user, carried out by the user authentication section 25, was successful; and a user information management database 26 for storing the Cookie information received by the second communication section 20. In a case where the authentication of the user, carried out by the user authentication section 25, was successful, the second communication section 20 (i) reads out, from the user information management database 26, Cookie information corresponding to user identification information for identifying the user and (ii) transmits the Cookie information to the multifunction apparatus 1.