The present technology relates to a sound source separation apparatus and a method which make it possible to separate a sound source at lower calculation cost. A communication unit receives a spatial frequency spectrum of a sound collection signal which is obtained by a microphone array collecting a plane wave of sound from a sound source, and a spatial frequency mask generating unit generates a spatial frequency mask for masking a component of a predetermined region in a spatial frequency domain on the basis of the spatial frequency spectrum. A sound source separating unit extracts a component of a desired sound source from the spatial frequency spectrum as an estimated sound source spectrum on the basis of the spatial frequency mask. The present technology can be applied to a spatial frequency sound source separator.