Abstract: When the presence of an RF ID tag is detected by a contactless reader/writer, an information processing terminal causes a contactless reader/writer to set a state flag in the RF ID tag to a first state which indicates that a wireless LAN communication unit of the mobile telephone is in an inactive state, and sends presence information indicating the presence of the mobile telephone to the information processing apparatus. When the state flag in the RF ID tag is set to the first state, the mobile telephone disables the wireless LAN communication unit. The information processing apparatus receives the presence information and stores the received presence information in a database.