This invention relates to a waste treatment furnace and method comprising: Generating a molten metal bed, which moves in a forward direction, such as to define a closed circuit in a cyclical and continuous manner, the surface of said bed comprising at least one essentially-slag-free segment. Loading waste onto the aforementioned essentially-slag-free segment, the waste being dragged by the molten metal bed such that it floats in the mentioned forward direction. Retaining the waste on the surface of the molten metal bed as it moves in the mentioned forward direction. Treating the waste under the effect of the constant and continuous heat exchange generated by the movement of the molten metal bed beneath the waste retained thereon.