The present disclosure relates to a technical idea of reducing the surface temperature of a material or temperature under a material by emitting heat under a device to the outside by absorbing and emitting long-wavelength infrared light corresponding to the wavelength range of the atmospheric window while minimizing absorption of light of the solar spectrum. More particularly, the present disclosure relates to a technology for providing a radiative cooling device having a multilayer structure that is capable of increasing sunlight reflection through differences in the refractive indexes of the device-forming materials while performing selective emission over the wavelength range of the atmospheric window using a radiative cooling device having a multilayer structure composed of polymers and inorganic materials.