A control device is mounted to one's own mobile body such as a vehicle for controlling its starting motion. A distance measuring part measures the distance to a front going vehicle and a speed control part controls the speed of the own vehicle such that the distance to the front going vehicle will be constant based on the measured distance. A stop control part serves to detect stopping of the front going vehicle and generates a stop control signal for the own vehicle. A start control part serves to detect a start of said front going mobile body and generates a start control signal for the own vehicle. An image-taking device serves to obtain an image of the front when the front going vehicle stops and another image when it starts again. The own vehicle is inhibited from automatically starting if these two images do not match.