A presentation system includes a screen device, a projecting device that projects a visible image onto the screen device, and a laser pointer operated by a user, that projects a laser beam onto the screen device. The laser pointer includes an infrared light emitting section and a laser beam emitting section. A projected image of the infrared light projected onto the screen is sensed by an infrared light sensing section. Movement direction and movement distance of the projected image and button click signal are converted into mouse data usable by computer. An image based on the mouse data from the computer is projected from a projector to the screen. A human body sensor which senses heat of human body existing in a projected direction of the laser beam is settled to supply a safe presentation system by controlling the projection of the laser beam in case this sensor is operated.