PROBLEM TO BE SOLVED: To provide a structure of a solid phase system that reversibly changes to a light scattering state at a temperature above the nematic-isotropic phase transition point temperature, and to a light transmission state at a temperature below the nematic-isotropic phase transition point temperature.SOLUTION: A structure of a solid phase system is configured of a liquid crystal material phase-separated in an anisotropic polymer being dispersed as liquid crystal drops. The phase of the liquid crystal material has optical anisotropic-isotropic change by the nematic-isotropic phase transition, and the phase of the anisotropic polymer has a refractive index in which a difference in refractive index between the phase of the anisotropic polymer and the phase of the liquid crystal material in a nematic state coincides for every independent polarization component. The structure of a solid phase system can be reversibly changed to a light scattering state at a temperature above the nematic-isotropic pha
