Heat transfer apparatus

In an apparatus wherein heat conductive members are disposed on respective surfaces of a plurality of heat generating bodies immersed in a liquid coolant, and heat of the heat generating bodies is removed by boiling of the liquid coolant;

• a heat transfer apparatus characterized in that each heat conductive member is formed with a plurality of layers of first cavity groups and second cavity groups which extend elongately in a manner to be partitioned by thermally-conductive plate members, said first cavity groups and said second cavity groups being stacked alternately in a direction perpendicular to the surface of the corresponding heat generating body, said first cavity groups being adapted to restrict vapors generated in each cavity of said first cavity groups from flowing out of said cavity and stably hold the vapors in said cavity, while said second cavity groups have open ends through which the liquid coolant in each cavity of the second cavity groups flows directly and the vapors generated in the cavity of said second cavity groups flows out directly to the outside of the cavity of said second cavity groups and, that said plate members are provided with openings which bring into communication said first cavity groups and said second cavity groups of the layers adjoining each other and a cavity group of the outermost layer and an outer space of said heat conductive member.