A mobile station includes a degradation detecting section (15) for detecting a degraded communication quality, an electric field measurement section (14) for measuring an intensity of an electric field, and a display unit (16) for representing a field level among a plurality of field levels. The display unit (16) represents, upon generation of the degraded communication quality, a fixed field level instead of the field level corresponding to the intensity of the electric field measured by the electric field measurement section (14).