Abstract: The present invention relates to a technical idea of cooling the surface of a material or the internal temperature under the material by emitting heat under an element to the outside while minimizing absorption of light in the solar spectrum, and more particularly to a technology for developing a material having a high transmittance or high reflectance with respect to incident sunlight and a high absorptivity selectively in a wavelength range of 8 ?m to 13 ?m corresponding to the sky window section of the atmosphere.

Abstract: The present invention relates to a technique of cooling a temperature on the surface or under a material by emitting heat under a radiative cooling device to the outside while minimizing the absorption of light in a solar spectrum by forming a paint coating layer with excellent radiative cooling performance on various surfaces. A radiative cooling device according to an embodiment of the present invention may include a paint coating layer formed by coating or dyeing on various surfaces a paint solution mixed with nano or microparticles of which a particle size and a composition are determined in consideration of infrared emissivity and reflectance to incident sunlight in a wavelength range corresponding to a sky window and a binder mechanically connecting the surfaces of the nano or microparticles in a solvent.