RECORDING MEDIUM

PURPOSE:To avert the damage of a glass substrate at the time of dropping a recording medium or other times by forming the resin substrate of the disk- shaped recording medium formed by sticking the resin substrate to the disk- shaped glass substrate to a diameter larger than the diameter of the glass substrate. CONSTITUTION:The resin substrate 5 formed to the diameter larger by a prescribed size than the diameter of the glass substrate 2 is stuck to the rear surface of the glass substrate 2 provided with a recording surface 3 on the front surface of the optical disk 1 and is partly projected radially from the circumferential end face of the glass substrate 2. The difference in the radii between the glass substrate and the resin substrate 5 is determined by taking the deformation and distortion of the resin substrate 5 by impact. As a result, the projecting part of the resin substrate 5 absorbs and can protect the glass substrate when the impact is applied from the circumferential end face direction of the optical disk to the central direction.