A cage drying--compacting apparatus for wastes, includes a cylindrical shape and at least a pair of pressure plates, the cylindrical body having heating longitudinal tubes, coursed by a thermal carrier fluid, provided along the generatrixes of the cylinder and spaced from each other to realize longitudinal slots for outlet of vapour but not for outlet of material, coupled by constraint hinge elements, positioned at a given distance between centres, and the pressure plates being placed opposed each other, operating as movable basis of the body and acting as pistons. Heat sources are, provided inside the apparatus, all along its length, the sources include at least a tube coursed by thermal carrier fluid, an inlet for the material to be treated, and elements for collecting the material.