As wireless LANs and wireless terminals deployed, security and authentication, among other things, became important. We propose a mutual authentication scheme for access security among wireless terminals. We use user identification together with hardware identification in creating a certificate for the wireless access. And authentication is performed based on the certificate. It enables reliable user authentication, establishment and check of access rights (when a terminal is managed in connection with a network gateway), Peer-to-Peer access with authentication, and international roaming of terminals.