A mobile terminal for judging by receiving a radio waveform sent from a particular base station whether or not the mobile terminal is located in a service area provided by the base station includes a signal receiver searching the base station by receiving the radio waveform from the base station, a processing unit setting an interval in response to the search result performed by the signal receiver, a request signal for searching the base station compulsory and a condition showing the period for being located out of the service area, and transiting the condition to another condition, and a control unit controlling the signal receiver to start searching the base station at the interval set by the processing unit.