An object detection apparatus for detecting a specific object in an input image includes a specific object detection module for performing a specific object detecting process of setting the input image or a reduced image of the input image as a target image, and of determining whether or not the specific object exists in a determination region while scanning the determination region in an edge feature image of the target image. The specific object detection module includes a determination module for determining whether the specific object exists in the determination region, based on an edge feature amount of the edge feature image corresponding to the determination region, and a previously determined relationship between an edge feature amount and a weight indicating object likelihood for each predetermined feature pixel in an image having the same size as the determination region.