Disclosed are a passenger counting device, etc., for accurately counting the number of occupants in a vehicle, including persons seated in the rear seats thereof. This vehicle passenger counting device comprises: a specific part detection means for detecting a specific part of a vehicle from acquired images and generating specific part detection results; an association means for associating the specific part detection results across images in order to compute a degree of movement of the vehicle and generate vehicle movement information including the result of the said computation; a person detection means for detecting persons who are occupants of the vehicle in the images and generating person detection results including location information of the detected persons; and an integration means for determining the number of occupants by integrating the person detection results on the basis of the vehicle movement information.