Heat generated at heat generating components is efficiently transported to a wall of a metal box serving as a heat dissipation section to cool the heat generating components even in an apparatus, in which box the heat generating components together with other components are mounted. The heat generating components and the heat dissipation section are connected to each other through a thermal transport device having a flexible structure. The heat generating components and the box are readily connected to each other irrespective of the arrangement of components, and heat is efficiently transported by driving the liquid. In the heat dissipation section, because the heat generating components and the wall of the metal box are thermally connected to each other, a high heat dissipation capacity is obtained as heat is diffused extensively into the wall due to a high thermal conductivity of the metal box.