An automatic gain control circuit includes a power calculator for calculating power of a modulation wave supplied to a demodulator; a power comparator for comparing the power calculated by the power calculator with ideal power of a modulation scheme of the modulation signal; a first gain controller for carrying out gain control of a first AGC amplifier in response to an output of the power comparator; and a second gain controller for carrying out gain control of the second AGC amplifier in response to the output of the power comparator. The automatic gain control circuit can solve a problem of a conventional AGC circuit in that precision gain distribution cannot be achieved to the two AGC amplifiers because the two AGC amplifiers are controlled by a single control signal output from the automatic gain control circuit.