A projection type image display device that projects images, the projection type image display device comprising: an image projecting unit that projects an image; at least one or more lighting units that illuminates or irradiates an illuminating light that is different from the projection light from the image projecting unit onto a manipulation surface which at least partially overlaps an image projection surface onto which the image projecting unit projects an image; an image capture unit that captures an image of the manipulation surface; a first detection unit that performs a first detection process to detect the position where a first object being manipulated that emits infrared light from a distal end, contacts the manipulation surface; a second detection unit that performs a second detection process to detect the position that a second object being manipulated that does not emit light, contacts the manipulation surface, and that is different from the first detection process; and a control unit that controls the operation of the projection type image display device, to change at least a part of the image that is projected by the image projecting unit based on detection results from the first detection unit or the second detection unit; wherein the control unit performs control to notify of a change in the state: when changing from the state where both the first detection unit and the second detection unit can perform detection, to a state where either one of the first detection unit or the second detection unit cannot perform detection; or when changing from the state where either one of the first detection unit or the second detection unit cannot perform detection to a state where both the first detection unit and the second detection unit can perform detection; and wherein the control unit performs control to notify of a change in the state by utilizing light emitted by the first object being manipulated. an image projecting unit that projects an image; at least one or more lighting units that illuminates or irradiates an illuminating light that is different from the projection light from the image projecting unit onto a manipulation surface which at least partially overlaps an image projection surface onto which the image projecting unit projects an image; an image capture unit that captures an image of the manipulation surface; a first detection unit that performs a first detection process to detect the position where a first object being manipulated that emits infrared light from a distal end, contacts the manipulation surface; a second detection unit that performs a second detection process to detect the position that a second object being manipulated that does not emit light, contacts the manipulation surface, and that is different from the first detection process; and a control unit that controls the operation of the projection type image display device, to change at least a part of the image that is projected by the image projecting unit based on detection results from the first detection unit or the second detection unit; wherein the control unit performs control to notify of a change in the state: when changing from the state where both the first detection unit and the second detection unit can perform detection, to a state where either one of the first detection unit or the second detection unit cannot perform detection; or when changing from the state where either one of the first detection unit or the second detection unit cannot perform detection to a state where both the first detection unit and the second detection unit can perform detection; and when changing from the state where both the first detection unit and the second detection unit can perform detection, to a state where either one of the first detection unit or the second detection unit cannot perform detection; or when changing from the state where either one of the first detection unit or the second detection unit cannot perform detection to a state where both the first detection unit and the second detection unit can perform detection; and wherein the control unit performs control to notify of a change in the state by utilizing light emitted by the first object being manipulated.