A beamforming apparatus is provided for improving beamforming accuracy by employing fractional delay filters in an interpolation process and reducing hardware complexity by using post-filtering technique. The beamforming apparatus of the present invention includes a post-filtering means implemented with fractional delay filters that combines block data, on the respective channels, supposed to be fractionally delayed and obtains a delay value of fractional part from the combined data. The post-filtering means collects the block data of the channels assigned identical coefficients and performs a filtering process simultaneously.