It is generally accepted that fusion power is one of the promising sources of sustainable energy in the future.However, there are many challenges towards the successful design of the "Fusion Reactor". One among them is the design of the "Divertor" which is an important part of the fusion reactor that handles extremely high heat and particle flux escaping from the hot core plasma region along Scrape-Off-Layer (SOL). The function of the divertor is to remove fusion ash, plasma impurities, and unburned fuel from the reactor which affects the quality of the plasma. This book described the various cooling concept, current development activities and future scope of the He-Cooled divertor for the fusion reactor.