Multilayer optical recording medium and optical recording method

A multilayer optical recording medium comprising:

• at least multiple information layers;
• wherein the multiple information layers each comprise at least a phase change recording layer capable of recording information by laser irradiation, and a reflection layer,
• wherein each information layer other than an innermost information layer as seen from a side of the laser irradiation comprises a lower protection layer, the phase change recording layer, an upper protection layer, the reflection layer and an optical transmission layer,
• the upper protection layer in each information layer other than the innermost information layer as seen from the side of the laser irradiation is composed of a material containing an oxide of Sn,
• the optical transmission layer in each information layer other than the innermost information layer as seen from the side of the laser irradiation is composed of a material containing SnO2 as the major component and In2O3, and
• a thickness of the upper protection layer in each information layer other than the innermost information layer as seen from the side of the laser irradiation is 2 nm to 15 nm, and
• wherein the reflection layer in each information layer other than the innermost information layer as seen from the side of the laser irradiation contains Cu as the major component and further contains at least one metal element selected from the group consisting of Mo, Nb and Ge at 5% by mass or less.