A cooling device employing a boiling cooling method cannot exhibit sufficient cooling performance when it is installed in a low-profile electronic device.A cooling device of the present invention comprises an evaporation unit which contains a refrigerant, a condensation unit which performs heat radiation by condensing and liquefying vapor-phase refrigerant which was vaporized at the evaporation unit, and piping which connects the evaporation unit with the condensation unit; wherein the evaporation unit comprises an evaporation container and a partition wall section which is arranged within the evaporation container and constitutes a flow path of the refrigerant, and the height of the partition wall section is equal to or larger than the height of the vapor-liquid interface of the refrigerant and is smaller than the height of the evaporation container.