Disclosed are a cellular phone terminal having built-in wireless LAN, a cellular phone system and a privacy protection method therefore that enable to prevent leakage of private information (or privacy) of the user of the cellular phone terminal from the communication data when conducting a search for wireless LAN base stations. The cellular phone terminal 10 comprises, in addition to the cellular phone function section 11, a cellular phone network transmitter/receiver section 14, a wireless LAN transmitter/receiver section 13 and a wireless LAN connection control section 12, an SSID•MAC address management section 15 connected to the wireless LAN connection control section 12 and the cellular phone network transmitter receiver section 14. The SSID•MAC address management section 15 is allocated by a MAC address management server 25 one or more temporary MAC addresses together with their time limit by way of the cellular phone network transmitter/receiver section 14 and a cellular phone base station 23 and the temporary MAC addresses are used when conducting a search for wireless LAN base stations 21.