Described is a unit (1) for feeding closing elements (34) for closing containers (2) defining capsules (3) for extraction or infusion beverages for a machine (100) for packaging capsules (3) for extraction or infusion beverages comprising: means (4) for feeding a web (5) of heat-sealable material along a predetermined path for feeding the web; a plurality of punches (6), positioned along the path for feeding the web of heat-sealable material in a region (R1) for forming the closing elements (34) and movable between an operating position (P1) wherein they make contact with the web (5) of heat-sealable material for cutting portions of the web, so as to form corresponding closing elements (34) and a non-operating position retracted relative to the web (5); a plurality of pickup units (GP1, GP2, GP3, GP4) each having a plurality of pickup means (7), each pickup unit (GP1, GP2, GP3, GP4) being movable individually along a closed path (PS2) between a pickup position (P3), wherein the respective pickup means (7) are located in the forming region (R1) for picking up the cut portions of the web (5) defining the closing elements (34), and a release position (P4) wherein the respective pickup means (7) are located in the release region (R2) for releasing the closing elements (34) picked up.