Furnace with movable beam load handling system, in particular for heating or heat treatment of ferrous or non-ferrous metallic material, comprising: - a furnace chamber extending between a furnace-loading section and a furnace-unloading section of the material along a longitudinal direction (X-X); - first beams, arranged inside said chamber and defining a plurality of main supports for the material to be treated in said chamber, extending in length between said furnace-loading section and said furnace-unloading section, spaced transversely apart from each other to support said material in different transverse positions in the furnace chamber, raised from a hearth of said chamber; - second beams, arranged inside said chamber and defining a plurality of temporary supports for the material, extending in length between said furnace-loading section and said furnace-unloading section, spaced transversely apart from each other and alternating with said main supports, wherein said second beams are cyclically movable with respect to the first beams so as to impart to said material a movement between said furnace-loading section and said furnace-unloading section having a motion component parallel to said longitudinal direction (X-X), characterized in that said first beams or said second beams, or both the first and the second beams, are movable with respect to the furnace chamber with movements having a motion component (Y-Y) transverse to said longitudinal direction (X-X), in order to generate relative movements between the material and the first beams transversally to said longitudinal direction (X-X) so as to cyclically vary the transverse resting positions of the material on the first beams. - a furnace chamber extending between a furnace-loading section and a furnace-unloading section of the material along a longitudinal direction (X-X); - first beams, arranged inside said chamber and defining a plurality of main supports for the material to be treated in said chamber, extending in length between said furnace-loading section and said furnace-unloading section, spaced transversely apart from each other to support said material in different transverse positions in the furnace chamber, raised from a hearth of said chamber; - second beams, arranged inside said chamber and defining a plurality of temporary supports for the material, extending in length between said furnace-loading section and said furnace-unloading section, spaced transversely apart from each other and alternating with said main supports, wherein said second beams are cyclically movable with respect to the first beams so as to impart to said material a movement between said furnace-loading section and said furnace-unloading section having a motion component parallel to said longitudinal direction (X-X), characterized in that said first beams or said second beams, or both the first and the second beams, are movable with respect to the furnace chamber with movements having a motion component (Y-Y) transverse to said longitudinal direction (X-X), in order to generate relative movements between the material and the first beams transversally to said longitudinal direction (X-X) so as to cyclically vary the transverse resting positions of the material on the first beams.