To provide a directory system capable of guaranteeing high security with a simple configuration.

All user information in which classified user information is included is stored in an authenticated directory 1, and disclosable user information is copied from the authentication directory 1 to a public directory 2. The authenticated directory 1 is guarded by a fire wall 3, and an X.509 digital certificate is required for performing access. A secret key for individual authentication is registered in a browser 50, and a secret key for system authentication is registered in a Web server 4, and those pen keys are registered in an authenticated directory 1. The authenticated user can register the user information in the authenticated directory 1 by using the Web browser 5. At this time, the classified information is designated. Thus the user can freely access the public directory 2, but needs an individual authentication and a system authentication is order to access the authentication system 1.