Mobile communication system

In a mobile communication system, a user managing section manages, as user managing information, a user ID of each user in association with a terminal ID of a currently activated one of mobile terminal equipments possessed by the user. Upon activating one of the mobile terminal equipments, the user managing section inactivates the currently activated mobile terminal equipment with reference to the user managing information. The mobile terminal equipment holds not only the terminal ID of the mobile terminal equipment but also the user ID. By notifying the user ID to the mobile communication system, activation and inactivation are controlled. If an input unit receives any user's operation while the mobile terminal equipment is inactivated, reception of the user's operation is informed to the mobile communication system and the mobile terminal equipment is automatically activated.