To make a driver easily recognize the danger of another vehicle.

This dangerous vehicle detection device acquires the extrinsic information of a vehicle by arranging a CCD camera which picks up the image of the neighboring exterior of the vehicle and a millimeter wave radar which measures a distance between its own vehicle and another vehicle, and detects and determines the existence of another neighboring vehicle viewed from its own vehicle and the traveling status based on the extrinsic information, and decides whether or not the other vehicle is under dangerous operation to its own vehicle. For example, when the other vehicle is under meandering operation with a traffic lane as a reference, and the vehicle is traveling deviating from the traffic lane in a predetermined time or more, it is determined that the vehicle is a dangerous vehicle. When the dangerous vehicle is detected, the driver of its own vehicle is urged to evade from the dangerous vehicle so as to contribute to safe driving by informing the driver of its own vehicle of information showing that the dangerous vehicle exists with an image or a voice (for the other vehicle, by notifying the driver of the information showing the fact).