Abstract: A user transmits, from an on-premises terminal or an off-premises terminal, his/her user ID and password as well as an address of a web page that the user attempts to access. A login authentication apparatus receives them and determines whether the received user ID, password and address of the web page match any of those stored in an authentication table within its master file. If they match, the login authentication apparatus transmits the address of the web page to a proxy server, so that the user is allowed to access the desired web page. Accordingly, the login authentication system ensures security on a web page basis within a web server, and the operation of the user is simplified.