The passenger counting system includes a photographing means 20 for photographing a vehicle and acquiring an image, and a passenger counting device 200. A passenger counting device 200 includes: a movement amount calculation means 21 for calculating a movement amount of a vehicle based on an image of the vehicle; a depth distance calculation means 22 for calculating a distance in a depth direction of a face of a passenger of the vehicle based on the movement amount of the vehicle; and a passenger number determination means 23 for detecting the face of the passenger of the vehicle from the image and determining the number of passengers of the vehicle based on distances in the depth direction of a plurality of detected faces of passengers.