To provide a radar apparatus for on-vehicle use that can determine whether or not an object existing in an azimuth detecting range has been detected.

A radar apparatus for on-vehicle use comprises a plurality of reception antennas constituting a reception array antenna having two or more types of average pitches not in a relationship of integral multiple to one another, and an azimuth detector that processes azimuth detection to detect the azimuth of an object on the basis of each of the signals of reception by each unit of the reception array antenna having two or more types of average pitches, and that, if the detected azimuths of the object are found identical, determines that the detected azimuths of the object are correct and, if the detected azimuths of the object are not found identical, determines that the detected azimuths of the object are incorrect.