There are provided a stereo matching method capable of increasing a resolution and precision of an object and a device for performing the method. The method includes investigating a pattern according to a predetermined period; obtaining left and right stereo images in which the investigated pattern is included or not included; determining whether each of the stereo image obtained according to the predetermined period and a buffering image that is a previous frame image of the stereo image includes the pattern; and generating a final cost volume by performing different image processing according to whether each of the stereo image and the buffering image includes the pattern. Therefore, it is possible to increase precision of a disparity of a thin object and increase accuracy and precision of an object at a long distance.