To provide an interfering wave detection circuit by which a center of interference is surely discriminated.

The proposed interfering wave detection circuit includes exclusive ORs 10-14 that provide a correlation between an in-phase signal RD' received from an input terminal 1 and an error signal RE, exclusive ORs 15-19 that provide a correlation between an inverted signal ID' received from an input terminal 2 and the error signal RE, integration devices 20-24 that integrate outputs from the exclusive ORs 10-14 to convert them into tap coefficients, integration devices 25-29 that integrate outputs of the exclusive ORs 15-19 to convert them into tap coefficients, adders 40-44 that respectively calculate the sum of absolute values of the tap coefficients outputted from the integration devices 20-24 and 25-29 in an identical time phase and those in the opposite phase, and a comparator 45 that compares the sums. A center of interference in an interfering wave is discriminated based on the comparison result of the sums.