A radar apparatus generates a strength distribution indicating a correspondence relationship between a relative speed parameter related to an observation point relative speed and a reflection strength parameter related to reflection strength of radar waves reflected at an observation point, for a plurality of observation points. Furthermore, the radar apparatus determines that a traveling vehicle is detected when the reflection strength parameter decreases as the relative speed parameter increases from a center relative speed parameter that is the relative speed parameter corresponding to a peak in the reflection strength, the reflection strength parameter decreases as the relative speed parameter decreases from the center relative speed parameter, and a distribution of the reflection strength parameter is symmetrical with the center relative speed parameter at the center.