A heat transfer element includes a container having a heat input section for receiving heat generated by a heating element and a heat output section for radiating the heat outside, and condensable working fluid that is vacuum-sealed in the container to transfer the heat received from the heat input section to the heat output section and that is moved between the heat input section and the heat output section by a capillary action member. The container is composed of a resin containing a thermoconductive material. A cooling device includes the heat transfer element, a heat sink disposed adjacent to the heat output section to radiate the heat received from the heat output section, and a fan for supplying cooling air to the heat sink.