A cooler grows in size and its structure becomes complicated in a phase-change cooler if it is intended to cool a plurality of heating elements; therefore, a phase-change cooler according to an exemplary aspect of the present invention includes a heat-conducting board configured to be thermally connected to a cooling object; heat receiving means for storing a refrigerant and receiving heat of the cooling object through the heat-conducting board; radiation means for radiating heat, condensing and devolatilizing a vapor-phase refrigerant arising from vaporization of the refrigerant in the heat receiving means; and connection means for connecting the heat receiving means and the radiation means.