To provide a wireless receiver and a received power estimating method with which a received power can be estimated with high accuracy at all times.

A signal received by an antenna 1 is subjected to various ways of signal processing, a GCA 7 with a variable gain amplifies the resulting signal, and an orthogonal demodulator 8 demodulates the amplified signal. A demodulation output level is given to a base band circuit 12, which generates a gain control signal and gives it to a gain control input of the GCA 7 via an exponential amplifier 17. The base band circuit 12 controls the voltage of the gain control signal, so that the demodulation level of the orthogonal demodulator 8 is always constant. Since a nearly linear relation holds between the voltage of the gain control signal generated by the base-band circuit 12 and a received power, the received power corresponding to the voltage of the generated control signal can be estimated with high accuracy.