This book systematically introduces the physical basis and theory of infrared radiation and the application of radiative cooling. It covers the geographical release of infrared radiation, infrared radiation material system, and preparation technology, infrared radiative cooling measurement and applications, the micro–nano-processing technology, the latest technology of radiative cooling and passive power generation, and the design of future application scenarios. The main content includes the current world energy application status and the development, research, and application status of radiative cooling technology, as well as the principle of radiative cooling technology, the research and application of different radiative cooling materials, the processing technology of radiative cooling devices, the development of radiative cooling technology, and other energy technologies. This book is used as reference for researchers and engineers who work in the fields of radiative cooling.