A cooling module includes a thermal conductive member. An endoergic chamber, a radiative chamber and a circulation pump chamber are defined along the thermal conductive member. The thermal conductive member contacts a heat generating object outside the endoergic chamber. The thermal energy is transferred to the coolant in the endoergic chamber. The coolant then flows into the radiative chamber. The thermal energy of the coolant is taken away in the radiative chamber. The thermal energy is radiated from the outer wall surface of the radiative chamber. This cooling cycle is repeated so that an efficient cooling operation can be realized in the cooling module. Arrangement of the endoergic, radiative and circulation pump chambers along the thermal conductive member leads to a minimized height of the cooling module.