It should be noted that in the case in which the distance (the projection distance) between the projector 100 and the projection surface is changed, the further from the optical axis CX of the projection lenses 210, 220 the cameras 310, 320 are disposed, the larger the change in position of the projection image in the taken image becomes. However, the second camera 320 disposed distant from the optical axis CX of the projection lenses 210, 220 compared to the first camera 310 is wider in field angle than the first camera 310, and can therefore include the projection image in the field angle even if the position of the projection image in the taken image changes.