1. An object detecting system for a vehicle, comprising: a radar which includes an electromagnetic wave transmitting means for transmitting an electromagnetic wave in a direction of movement of the vehicle, and a reflected wave receiving means for receiving a reflected wave from an object existing ahead of the vehicle in the direction of movement of the vehicle; and a determining means for determining presence or absence of an obstacle in the direction of movement of the vehicle based on a result of detection by said radar, wherein said radar can detect objects in each of a plurality of vertically different detection areas, and wherein the detection areas are established so that an overlapped region, produced by overlapping of the detection areas, includes a region parallel to a travel road surface.