Provided is a predistortion apparatus which performs predistortion by reflecting a memory effect when linearizing an output of a nonlinear device using a wideband signal. The predistortion apparatus includes a predistortion unit and a coefficient extraction unit. The predistortion unit selects and outputs one of outputs of the sub-predistorters as an output signal according to intensity of an input signal. The coefficient extraction unit selects one of a plurality of coefficient extractors according to intensity of a nonlinear signal which is generated in response to the output signal, extracts a plurality of predistortion coefficients with the nonlinear signal and the output signal, and delivers the extracted predistortion coefficients to the predistortion unit. Accordingly, the memory effect is reflected even when the input signal is a wideband signal.