A cooling module designed so that the following components are stacked above a CPU: a cooling jacket allowing a cooling liquid to absorb heat generated by the CPU, a pump causing the cooling liquid to circulate, a reserve tank used to provide a supplementary cooling liquid and to bleed air from the cooling liquid, and a first radiator that cools the cooling liquid, the cooling module being also designed so that a second radiator is located at a side of the first radiator to cool the cooling liquid, wherein the cooling liquid is driven by the pump so as to circulate from the cooling jacket, which absorbs heat generated by the CPU, through the radiators to the reserve tank.