Abstract: The present invention relates to a device and method for detecting a three-dimensional object using a plurality of cameras that are capable of simply detecting a three-dimensional object. The device comprises: a planarization unit for planarizing, through homography conversion, each input image obtained by the plurality of cameras; a comparison-area selecting unit for selecting each area to be compared after adjusting the offset of a camera in order to overlay a plurality of images which have been planarized by said planarization unit; a comparison-processing unit for determining whether or not corresponding pixels are identical in the comparison area selected by said comparison-area selecting unit, and generating a single image based on the results of the determination; and an object-detecting unit for detecting a three-dimensional object disposed on the ground by analyzing the form of the single image generated by said comparison-processing unit.