A slide fastener stringer includes a row of helically coiled or zig-zag coupling elements of thermoplastic synthetic resin with a reinforcing core extending longitudinally therethrough. The coupling elements are secured to one surface of a stringer tape by sewing threads having portions running across and over upper legs of the coupling elements. Some of the coupling elements are cut off to provide an element-free space on the stringer tape. A terminal or endmost complete coupling element disposed adjacent to the element-free space has a free-ended connecting portion remote from a longitudinal edge of the stringer tape. To form an end of the slide fastener stringer, the free-ended connecting end portion of the terminal coupling element is fused to the stringer tape, and at the same time, the upper leg of the terminal coupling element is heated and pressed toward the stringer tape. A device for forming such a stringer end includes a stringer rest for supporting the end of the stringer, and a heating presser having a first surface for heating and pressing the free-ended connecting portion of the terminal coupling element against the stringer tape and a second surface for heating and pressing the upper leg of the terminal coupling element toward the stringer tape. The first surface projects beyond the second surface toward the stringer rest.