Provided is a predistorter for compensating a memory effect to occur in an amplifier used in a communication device, especially an electric memory effect. The predistorter comprises a distortion compensation circuit (8) for compensating a nonlinear distortion caused by an amplifier (3), and inputs a predistortion signal outputted from the distortion compensation circuit (8), to the amplifier. Between the distortion compensation circuit and the amplifier, first filter means (21) is connected for compensating the frequency characteristics which appear in a signal component to occur in the entire analog circuit containing the amplifier. Between the distortion compensation circuit and the first filter means or between the first filter means and the amplifier, second filter means (22) is connected for compensating the frequency characteristics which appear in the distortion component to occur in the amplifier.