A detection device includes: a first sensor which detects, based on a captured image, whether a person is present in a first detection range; a plurality of second sensors which are disposed around the first sensor, and detect, based on infrared radiation, whether a person is present in respective second detection ranges each of which overlaps at least a portion of the first detection range; and at least one hood which blocks part of infrared radiation directed to at least one of the plurality of second sensors, to reduce a non-overlapping portion of a combined detection range of the first detection range of the first sensor and the second detection ranges of the plurality of second sensors, the non-overlapping portion being a portion in which the first detection range and the second detection ranges do not overlap.