Each of fins is provided with an engage projection having a first width and a engage hole portion having a second width wider than the first width, and the fins are able to be slid while engaging with each other. Accordingly, in case of installing a heat sink to a case of a fan, it is possible to install the fins to the case so that the fins are arranged in a flowing direction of a refrigerant by the fan while engaging with each other. As the result, the refrigerant is able to flow smoothly when passing through the fins by arranging the fins at desired angle. Accordingly, it becomes possible to present a radiation fin, a cooling device and an electronic equipment having such cooling device.