This stereo camera system is constituted of a stereo optical module which acquires a stereo image, a central control unit which evaluates an object as a target based on the stereo image acquired by the stereo optical module, and a communication line through which stereo image data output from the stereo optical module is input to the central control unit. Further, in this stereo camera system, an image output processing circuit which performs predetermined image processing with respect to the stereo image acquired by the stereo optical module is provided in the stereo optical module, whereby this image output processing circuit performs a correction arithmetic operation which corrects unbalance at the time of capturing the stereo image.