A distortion compensator compensates for distortion arising in an amplifier that amplifies a signal with improved efficiency. The distortion compensator includes a signal level detector which detects the level of a signal to be amplified by an amplifier, a distortion compensation execution unit which executes distortion compensation on the signal to be amplified according to a mode of distortion compensation corresponding to the signal level detected by the signal level and a correspondence between signal levels and distortion compensation control values as pairs, a distortion compensation control value correspondence updater which updates the correspondence between the signal levels and the distortion compensation control values used in the execution of distortion compensation, and a distortion compensation control value number controller which controls the values of stipulated parameters.