PURPOSE: To record information with high density or to accurately reproduce the information recorded with high density by providing a shutter layer incorpo rating semiconductor particles on a base plate.

CONSTITUTION: The optical disk 1 is provided with the base plate 11, a shutter layer 17 formed to the base plate 11 and an optical reflection layer 19 formed on the shutter layer 17. The base plate 11 is formed usually to be a disk, a flat face 11a is formed to the side face of the base 11 toward the light source of light beams and plural information pits 12 corresponding to information such as an audio signal and a video image, etc., are formed to the other side 11b. The shutter layer 17 is formed by scattering semiconductor particles selected by CdS or amorphous Si, etc., into a glass or resin matrix to stop the diameter of an optical beam radiating from the base 11 for read or write. Thus, pits with high density recording having not been read in a conventional disk are surely read.