Abstract: Provision of a projector used for a planetarium which is capable of reducing electrical power consumption and size. The projector comprises a light source 1 constituted by an array of a plurality of light emitting diodes L for emitting illumination light. The emitted illumination light passes through a condenser lens 2 to impinge onto a original projection plate 3 provided with a light-permeable pattern P, and then a transmitted image is projected through a projection lens onto a dome screen.