An interference wave detecting device comprises a transmitter for converting data to be transmitted from a base station into a radio signal of a predetermined transmission frequency, and for transmitting the radio signal to a mobile station by way of a transmitting antenna, a receiving unit for receiving either of a radio signal lying within a certain reception band of frequencies including a predetermined reception frequency from the mobile station and an interference wave signal lying within a certain transmission band of frequencies including the predetermined transmission frequency, and a controlling unit for causing the transmitting unit to stop transmitting the radio signal of the predetermined transmission frequency in order to detect the interference wave signal, and for enabling the receiving unit to receive the interference wave signal only within a period of time during which the transmitting unit stops transmitting the radio signal of the predetermined transmission frequency to the mobile station.