A distortion compensation apparatus having a circuit configured to perform power amplification of a transmission signal; and a circuit configured to feedback the transmission signal output from the circuit configured to perform power amplification and obtain a demodulated signal of the transmission signal, while calculating and holding a distortion compensation coefficient with which an error between the demodulated signal and the transmission signal before the power amplification becomes minimum, to perform distortion compensation of the transmission signal based on the distortion compensation coefficient and provide the compensated transmission signal to the circuit configured to perform the power amplification, the distortion compensation apparatus includes: a gain adjustment unit to adjust a gain of the transmission signal; and a gain control unit to adaptively adjust a gain of the gain adjustment unit based on the held distortion compensation coefficient.