Provided is a radar device includes a transmitting unit, a receiving unit for receiving the electromagnetic wave reflected by a target object of the transmission electromagnetic wave, a target object measuring unit for measuring at least a distance between the radar device and the target object on the basis of the transmission and reception electromagnetic waves, a transmission output control unit (S1, S2) for stopping or reducing a transmission output of the transmitting unit under a predetermined condition, a transmission output control function abnormality determining unit (S3 to S6) for determining that the transmission output control unit is abnormal upon receiving the reception electromagnetic wave having an intensity exceeding a predetermined threshold value even at the time of one of stop and reduction of the transmission output, and an abnormality determination time processing unit (S7) for stopping a power supply of the radar device when an abnormality is determined.