The radar apparatus includes a target candidate detecting means for detecting a peak frequency at which the intensity of the power spectrum of a beat signal peaks as a target candidate, a road shape recognizing means to sequentially connect, along a predetermined direction, the target candidates detected to be stationary and present within a reference distance from one of the target candidates set as a reference target candidate for one or more measurement cycles and recognize an area formed by the sequentially connected target candidates as an edge of the road, a cruise environment estimating means to determine whether the cruise environment is a closed space or an open space based on the power spectrum, and a reference distance correcting means to shorten the reference distance when the cruise environment is determined to be a closed space.