A method of determining the present electric field state of a mobile station also in view of an uplink electric field state is disclosed. A TPC bit counter is supplied with a received signal processed by a baseband processor, and counts TPC bits contained in one radio frame. An electric field state determining unit measures the electric field strength of the received signal from the base station which has been received by an RF receiver. A received electric field strength measuring unit determines a TPC bit evaluation value from the TPC bit sum calculated by TPC bit counter, determines a received electric field strength evaluation value from the received electric field strength measured by the electric field state determining unit, multiplies the TPC bit evaluation value by the received electric field strength evaluation value to calculates an electric field state evaluation value, and controls an alarm unit, a display unit, and an LED unit based on the calculated electric field state evaluation value for thereby indicating the electric field state.