A cooling device comprising a first heat receiving unit and a second heat receiving unit that receive heat generated by heat generating elements (220, 230); a first heat dissipating unit that has a first principal surface and dissipates the heat received by the first heat receiving unit; and a second heat dissipating unit that has a second principal surface and dissipates the heat received by the second heat receiving unit; a first pipe unit (500, 600) that connects the first heat receiving unit and the first heat dissipating unit for circulating refrigerant between the first heat receiving unit and the first heat dissipating unit; and a second pipe unit (510, 610) that connects the second heat receiving unit and the second heat dissipating unit for circulating refrigerant between the second heat receiving unit and the second heat dissipating unit; wherein the first pipe unit (500, 600) includes a first vapor pipe and a first liquid pipe, the first vapor pipe connecting the first heat receiving unit and the first heat dissipating unit and conveying refrigerant from the first heat receiving unit to the first heat dissipating unit, the first liquid pipe connecting the first heat receiving unit and the first heat dissipating unit and conveying refrigerant from the first heat dissipating unit to the first heat receiving unit; the second pipe unit (510, 610) includes a second vapor pipe and a second liquid pipe, the second vapor pipe connecting the second heat receiving unit and the second heat dissipating unit and conveying refrigerant from the second heat receiving unit to the second heat dissipating unit, the second liquid pipe connecting the second heat receiving unit and the second heat dissipating unit and conveying refrigerant from the second heat dissipating unit to the second heat receiving unit; the first principal surface and the second principal surface are arranged so as to face to each other, wherein air passes through the first heat dissipating unit and the second heat dissipating unit in a direction approximately perpendicular to the first principal surface and the second principal surface and from the first heat dissipating unit toward the second heat dissipating unit, and the first vapor pipe is connected to a first end of the first heat dissipating unit; and the second vapor pipe is connected to a second end of the second heat dissipating unit adjacent a second end of the first heat dissipating unit, the second end of the first heat dissipating unit being an opposite end to the first end of the first heat dissipating unit. a first heat receiving unit and a second heat receiving unit that receive heat generated by heat generating elements (220, 230); a first heat dissipating unit that has a first principal surface and dissipates the heat received by the first heat receiving unit; and a second heat dissipating unit that has a second principal surface and dissipates the heat received by the second heat receiving unit; a first pipe unit (500, 600) that connects the first heat receiving unit and the first heat dissipating unit for circulating refrigerant between the first heat receiving unit and the first heat dissipating unit; and a second pipe unit (510, 610) that connects the second heat receiving unit and the second heat dissipating unit for circulating refrigerant between the second heat receiving unit and the second heat dissipating unit; wherein the first pipe unit (500, 600) includes a first vapor pipe and a first liquid pipe, the first vapor pipe connecting the first heat receiving unit and the first heat dissipating unit and conveying refrigerant from the first heat receiving unit to the first heat dissipating unit, the first liquid pipe connecting the first heat receiving unit and the first heat dissipating unit and conveying refrigerant from the first heat dissipating unit to the first heat receiving unit; the second pipe unit (510, 610) includes a second vapor pipe and a second liquid pipe, the second vapor pipe connecting the second heat receiving unit and the second heat dissipating unit and conveying refrigerant from the second heat receiving unit to the second heat dissipating unit, the second liquid pipe connecting the second heat receiving unit and the second heat dissipating unit and conveying refrigerant from the second heat dissipating unit to the second heat receiving unit; the first principal surface and the second principal surface are arranged so as to face to each other, wherein air passes through the first heat dissipating unit and the second heat dissipating unit in a direction approximately perpendicular to the first principal surface and the second principal surface and from the first heat dissipating unit toward the second heat dissipating unit, and the first vapor pipe is connected to a first end of the first heat dissipating unit; and the second vapor pipe is connected to a second end of the second heat dissipating unit adjacent a second end of the first heat dissipating unit, the second end of the first heat dissipating unit being an opposite end to the first end of the first heat dissipating unit.