Disclosed herein are an apparatus and method for removing a self-interference signal. The apparatus includes one or more processors and executable memory for storing at least one program executed by the one or more processors. The at least one program receives an upstream signal for removing self-interference, generates a downstream signal for channel estimation, replicates a self-interference signal in a time domain and a self-interference signal in a frequency domain using the upstream signal and the downstream signal, and removes the self-interference signal from the upstream signal using the replicated self-interference signal in the time domain and the replicated self-interference signal in the frequency domain.