A compensation apparatus compensates a quadrature-demodulated signal output from a quadrature demodulator 5 that performs quadrature demodulation by using a signal of a carrier frequency fc, by removing an image component caused by the quadrature demodulator 5 from the quadrature-demodulated signal. The compensation apparatus includes a signal generator 10 that generates a reference signal having a predetermined bandwidth in a reception band, and provides the reference signal to an input side of the quadrature demodulator 5. The reference signal includes a frequency band that is biased to either a higher-frequency side or a lower-frequency side with respect to the carrier frequency.