PURPOSE: To easily and exactly display the blue sky changing in seasons during one year by providing a disk-shaped starry sky display body displaying stars on the under surface of a high-brightness light source and displaying the stars indicating the changes in one year on the starry sky display body.

CONSTITUTION: High-brightness light sources 2 disposed at prescribed intervals on a ceiling surface 1 are constituted of 250W high-pressure discharge lamps at, for example, 0.5m intervals. The starry sky display body 3 disposed freely rotatably under these light sources 2 are constituted to a disk shape of, for example, diameter 23m position. This starry sky display body 3 is constituted to display the starts of one year around the place of installation and to display the changes in one year in one turn. The display body 3 constituted of, for example, an iron plate is constituted by providing many small holes in the positions of the starts in order to display the constellation on the starry sky display body 3. A light transmissive resin plate is superposed atop the display body 3. The stars are made to appear at the points exclusive of a cover body 4 by this cover body 4 formed to cover a part of the under surface of the starry sky display body 3. The display body 3 is made to advance at a prescribed scale by using a cam.