PURPOSE: To enable the reflection of most of heat rays in a near IR region in which energy radiated from the sun is concentrically present by holding a volume phase type holographic diffraction grating layer for reflecting IR between each of the two transparent glass sheets and the middle layer of sandwich glass.

CONSTITUTION: A volume phase type holographic diffraction grating layer 2 for reflecting IR is held between each of the two transparent glass sheets 1 and the middle layer 3 of sandwich glass to form a heat ray reflecting glass. This heat ray reflecting glass reflects 80-90% of heat rays having 0.8-2μm wavelength in a near IR region in which energy radiated from the sun is concentrically present.