To provide a log-in authentication system capable of preventing an illegal access, by a novel configuration.

An authentication device 1 stores at least a biometric authentication software for display-outputting a prescribed authentication screen, and for controlling a biometric authentication means 11 to authenticate a user biometrically, a product authentication software for transmitting an authentication request token including identification information different the user by the user and an accumulated use time to an authentication server 41, and for receiving a product authentication token for a reply when the authentication server 41 confirms the continuity of the accumulated use time, so as to authenticate a product, and a use time notification software for notifying the accumulated use time in the present, to the authentication server 41, in every prescribed time, and a usual operation by an OS of a communication terminal device 3 is allowed after the biometric authentication and the product authentication, when an electric power source is fed to the communication terminal device 3.