PURPOSE:To obtain a master disk containing tracking guides and signal information pits of high accuracy, by providing successively a signal information producing layer and a tracking guide forming layer on a substrate by means of different photosensitive materials and exposing these layers with variation of quantity of laser light. CONSTITUTION:A signal information producing layer 2 is formed on a glass substrate 1 having a polished surface by applying the vacuum vapor deposition of a metal (including an alloy) such as Te, Al, which can be removed with the laser light in the form of the 1st photosensitive material. Then a tracking guide layer 3 is formed on the layer 2 by coating with a spinner a photoregister layer 3 in the form of the 2nd photosensitive material. A tracking guide part 5 is formed with exposure to the layer 3 with the laser light condensed by a lens 4. During this process, the light quantity is increased at a desired position to form signal information pits to the layer 2. Then the developing and fixing processes are applied to the layer 3 to obtain a master of an optical disk containing guide parts 6 and signal information pits 7. Thus the efficiency of production is improved for master disks for information storing media with high accuracy.