Patent ID: 7035190

Claim:
A method for recording/reproducing an information recording medium, wherein the information recording medium comprises a first information layer and a second information layer, wherein the first information layer comprises a first recording layer in which a reversible phase change is caused between a crystalline phase and an amorphous phase by irradiation of a laser beam or Joule heat generated by application of current, the second information layer comprises a second recording layer in which a reversible phase change is caused between a crystalline phase and an amorphous phase by the irradiation of the laser beam or the Joule heat generated by the application of the current, the first recording layer is made of a first material that comprises Ge, Sb, and Te, the second recording layer is made of a second material that comprises Sb, Te, and at least one element Ml selected from the group consisting of Ag, In, Ge, Sn, Se, Bi, Au and Mn, and the first material is different from the second material, and with respect to the first information layer of the information recording medium, information is recorded/reproduced with a laser beam incident from a side of the first information layer, with respect to the second information layer of the information recording medium, information is recorded/reproduced with the laser beam that has passed through the first information layer, and a wavelength of the laser beam is in the range of 390nm or more and 430nm or less.