A stereo camera apparatus which carries out distance measuring stably and with high accuracy by making measuring distance resolution variable according to a distance to an object is provided. A stereo camera apparatus 1 takes in two images, changes resolution of a partial area of each image that is taken in, and calculates a distance from a vehicle to an object that is imaged in the partial area, based on disparity of the partial area of each image in which resolution is changed. Thus, even when the object exists at a long distance and is small in size, distance measuring processing can be carried out stably.