A photographing section photographs a photographing object, a light-projector projects a light spot parallel to or approximately parallel to an optical axis of the photographing section onto the photographing object, and a detector detects, from an image of the photographing object photographed by the photographing section, a light spot from the light-projector reflected by the photographing object on the basis of an arrangement position of the light-projector relative to the photographing section. A reflected light spot of light projected onto a detection object can be detected with certainty, and erroneous detection of the reflected light spot, in particular, erroneous detection due to disturbance light, can be prevented at a low cost, without an increase in size of the apparatus.