An abnormality detection apparatus, comprises a first acquisition unit configured to acquire imaged data obtained by imaging an object vehicle traveling on a road; a first recognition unit configured to recognize a lighting state of lighting devices of the object vehicle, based on the imaged data; a second recognition unit configured to recognize a lighting necessity of the lighting devices, based on the imaged data; and a detection unit configured to detect whether the lighting devices operate normally or abnormally, based on the lighting state and the lighting necessity.