Digital filter device, and digital filtering method

In order to solve achieve the distortion compensation with high accuracy, a digital filter apparatus comprising: a first distortion compensating filter unit for processing the input digital signal comprises a first signal waveform distortion distortion compensation performed; first filter coefficient setting means for setting a filter coefficient of the first distortion compensating filter unit; a second distortion compensating filter means for compensating comprises a second waveform from the first distortion compensating signal output from the filter unit distortion; and a second filter coefficient setting unit, based on the filter coefficient setting unit by the first filter coefficient, the second filter coefficient set distortion compensating filter unit.