PURPOSE: To eliminate the need of basting of a tuck stitch executed in a separate process and to enhance the quality of a tuck stitch shirt, etc., by tucking a tuck into the back body part in a trapezoidal shape inclined to a sewing part of a sewing machine, joining the surface and the back shoulder yokes to the back body part brought to tuck stitch, pressing slightly with a holding plate and feeding it into the dewing part, and seaming and sewing the back shoulder yoke to the back body part.

CONSTITUTION: On the upper face of the back body part B in which a tuck C is tucked by a tuck plate 56, a surface shoulder yoke D whose upper and lower ends are reversed is placed and attached. Subsequently, three pieces of cloth are pressed against the upper face of the surface shoulder yoke D with the front end of a first holding plate 28a by turning a first holding plate 28a, and to the upper face of this first holding plate 28a, the surface shoulder yoke D is folded and brought to forward turn, and also, a second holding plate 28b is turned forward, and in a position being adjacent to the folding part of the surface shoulder yoke D, the upper face of the back body part B is pressed. A back shoulder yoke A and the back body part B superposed by the front part of a ruler 20, and the surface shoulder yoke D superposed and reversed to the upper face of a first holding plate 28 are both guided to the sewing part 14 of the side, fed into the lower part of a sewing machine needle 15 through a guide plate 76, and they are sewn, while operating the sewing machine needle.