A heat conductive plate includes a hollow case and a plurality of grooves respectively formed on the inner top wall and the inner bottom wall of the case. In addition, a plurality of supporting members are positioned in the case by way of powder sintering, wherein each surface of the supporting members has a porous wick structure formed thereon. Thus, the case can be sustained by the supports with each wick structure firmly mounted in the grooves of the inner walls thereof. When performing heat transferring, the working fluid is heated to be formed as vapor by the electronic element mounted on the outer bottom surface so as to flow toward the inner top surface of the case. The working fluid is then cooled to be liquid again to be absorbed by the wick structures of the supporting members and be transported toward the inner bottom of the case.