A heat exchange furnace includes a surrounding wall disposed around a combustion furnace unit so as to define an annular heat exchange space therebetween. Upright buffer plates divide the heat exchange space into a plurality of air chambers communicated with each other. Upper and lower gas-guiding members are connected respectively and fixedly to upper and lower ends of the surrounding wall. Conduit sets are disposed within the heat exchange space, and cooperate with the upper and lower gas-guiding members so as to constitute cooperatively at least one serpentine gas flow path disposed within the heat exchange space.