<p>An advertisement delivery system capable of delivering advertisements the contents of which are wanted by users, while maintaining the security concerning the user information. In a network environment including an Internet connection apparatus that relays and connects a LAN environment and an Internet environment, an advertisement delivery system uses the Internet connection apparatus to receive and store information concerning a user using an device connected to the LAN environment; compares the attribute information of the received advertisement content data with stored user information to thereby screen the advertisement content data; receives and stores the advertisement content data to be delivered from a device used by an advertisement content distributor; and delivers advertisement content data in response to a request; wherein only when there exists a coincidence between the attribute information of the advertisement content data and the user information, the whole of that advertisement content data is delivered from the device used by the advertisement content distributor.</p>
