PURPOSE: To enable information recording with high sensitivity by the construction in which different metallic films are alternately laminated in the state of extremely thin films.

CONSTITUTION: Part of an energy beam such as laser light is converted to heat energy when said beam is irradiated to the extrathin film layer 2 consisting of a metal A and the extrathin film layer 3 consisting of a metal B laminated alternately on a substrate 1. A satisfactory alloying reaction does not arise by the energy beam of low output with the film formed simply by laminating each one layer of the relatively thick film layer consisting of the metal A and the film layer consisting of the metal B in this stage. Whereas, the satisfactory alloying reaction is progressed even by the energy beam of the low output with the films 5 laminated with the metal A and metal B in the extremely thin film state. The optical characteristic such as reflectivity of light is eventually changed and the information is recorded. The thickness of each thin metallic film of the layer 5 is thus required to be made as small as possible and the number of the laminated layers is required to be increased in order to improve the recording sensitivity.