A subscriber unit and a radio base station recognition method whereby the most serviceable radio base station can be automatically recognized at a fixed location. Radio base station detecting unit detects, in a continuous receive mode, radio base stations from which radio wave can be received. Area number recognizing unit recognizes an area number of radio base stations of which location registration is permitted, and radio base station extracting unit extracts radio base stations with the area number from among the detected radio base stations. Synchronization control unit establishes synchroneity with a radio base station of highest reception level among the extracted radio base stations.