A detection device includes: a first detector which irradiates light onto the target object and detects light emitted from the target object; a first shape information generator which generates first shape information representing a first shape of the target object on the basis of a detection result of the first detector; and a second shape information generator which adds a second shape, which is based on information different from the detection result of the first detector, to the first shape, and which generates second shape information representing a shape including the first shape and the second shape.