A universal automated stacking device comprising a pre-stacking table and a claw, wherein - the pre-stacking table is configured to make a package of pieces and comprises a plurality of support assemblies attached onto a chassis and at least one side centering device configured to align the package of pieces on the support assemblies, and each support assembly is attached to at least one guide to be selected among a lead guide and a rear guide of the chassis, and - the claw is configured to fasten said package of pieces to be carried to create the stack on a pallet and comprises at least one pair of pliers attached to a frame, wherein the at least one pair of pliers is fixed to the frame via an arm which is attached to a crossbar that is in turn attached to a rail located in the lower part of the frame, and each arm is attached to a slide of the crossbar, and H wherein each support assembly comprises: - a conveyor belt which comprises at least one belt, - a support arm, and - a lower beam onto which both the conveyor belt and the support arm are supported, such that the support assemblies are attached to the lead and rear guides (20, 21) via the lower beam, and the support arm comprises at least one support abutment configured to be positioned throughout said support arms to adapt to different widths of the pieces and contribute to the centering of each piece on the support arm, wherein both the pre-stacking table and the claw comprise a plurality of actuations to adapt their components to the different dimensions of the pieces, such that each support assembly has capacity of displacement on the guide (20, 21) of the chassis, each crossbar has capacity of displacement along the rail displacing the pairs of pliers, and the arms have capacity of displacement along the slide displacing the pliers of each pair. - the pre-stacking table is configured to make a package of pieces and comprises a plurality of support assemblies attached onto a chassis and at least one side centering device configured to align the package of pieces on the support assemblies, and each support assembly is attached to at least one guide to be selected among a lead guide and a rear guide of the chassis, and - the claw is configured to fasten said package of pieces to be carried to create the stack on a pallet and comprises at least one pair of pliers attached to a frame, wherein the at least one pair of pliers is fixed to the frame via an arm which is attached to a crossbar that is in turn attached to a rail located in the lower part of the frame, and each arm is attached to a slide of the crossbar, and H wherein each support assembly comprises: - a conveyor belt which comprises at least one belt, - a support arm, and - a lower beam onto which both the conveyor belt and the support arm are supported, such that the support assemblies are attached to the lead and rear guides (20, 21) via the lower beam, and the support arm comprises at least one support abutment configured to be positioned throughout said support arms to adapt to different widths of the pieces and contribute to the centering of each piece on the support arm, wherein both the pre-stacking table and the claw comprise a plurality of actuations to adapt their components to the different dimensions of the pieces, such that each support assembly has capacity of displacement on the guide (20, 21) of the chassis, each crossbar has capacity of displacement along the rail displacing the pairs of pliers, and the arms have capacity of displacement along the slide displacing the pliers of each pair. wherein the at least one pair of pliers is fixed to the frame via an arm which is attached to a crossbar that is in turn attached to a rail located in the lower part of the frame, and each arm is attached to a slide of the crossbar, and H wherein each support assembly comprises: - a conveyor belt which comprises at least one belt, - a support arm, and - a lower beam onto which both the conveyor belt and the support arm are supported, such that the support assemblies are attached to the lead and rear guides (20, 21) via the lower beam, and - a conveyor belt which comprises at least one belt, - a support arm, and - a lower beam onto which both the conveyor belt and the support arm are supported, such that the support assemblies are attached to the lead and rear guides (20, 21) via the lower beam, and the support arm comprises at least one support abutment configured to be positioned throughout said support arms to adapt to different widths of the pieces and contribute to the centering of each piece on the support arm, wherein both the pre-stacking table and the claw comprise a plurality of actuations to adapt their components to the different dimensions of the pieces, such that each support assembly has capacity of displacement on the guide (20, 21) of the chassis, each crossbar has capacity of displacement along the rail displacing the pairs of pliers, and the arms have capacity of displacement along the slide displacing the pliers of each pair.