A thread chain sewing apparatus for use in overedge sewing machines has a thread chain catcher with a cutter for cutting a thread chain formed to extend from an end of a fabric and suctionally engaged against a suction opening. A presser foot having a guide groove for insertion of the thread chain is movable up and down, and a thread chain carrier is aligned with the thread chain catcher and has a suction nozzle for suctionally receiving the cut-off thread chain to carry it over the presser foot. An air blow tube running under the throat plate can be provided, an aperture thereof blowing the chain toward the suction opening. A thread chain presser mechanism has a holding plate movable up and down over the presser foot for pressing the thread chain into the guide groove of the presser foot. The apparatus operates such that the thread chain is sewn in while being positioned on the upper side of a next piece of fabric and without friction with the fabric, and is arranged such that an operator can watch as the thread chain is actually sewn in during the operation.