1. A data processing apparatus for a millimeter-wave radar, which receives data concerning peaks appearing in a frequency spectrum of a beat signal produced by mixing a received signal with a portion of a transmitted signal frequency-modulated by a triangular wave increasing and decreasing alternately in a cyclic fashion, and which processes the peak data for the increasing and decreasing sections of the triangular wave for a plurality of angles, comprising: part for determining pairing between peaks in the increasing section of the triangular wave and the corresponding peaks in the decreasing section thereof; part for calculating, from frequencies of the paired peaks, distance to each individual target and relative velocity of the target; and part for determining an ineligible target based on the calculated relative velocity.