A detection device includes an image acquisition section that acquires an image that has been captured by an imaging section, and includes an image of an object, a distance information acquisition section that acquires distance information about the distance from the imaging section to the object, a feature quantity calculation section that calculates a feature quantity from the image, a learning feature quantity storage section that stores a learning feature quantity calculated by a learning process corresponding to each of a plurality of distance ranges that are set corresponding to the distance from the imaging section to the object, and a detection section that determines a distance range that corresponds to the feature quantity based on the distance information, and detects the target area based on the learning feature quantity that corresponds to the determined distance range, and the feature quantity calculated by the feature quantity calculation section.