To sew string materials stably in a state that their folds are fixed and to prevent a member for forwarding the string material from catching the string material.

Rotation of a rotary body 13 is controlled in accordance with a moving direction of a fabric based on embroidery data, the direction of a guide mechanism is changed so that a guide direction of the string material A to a needle base becomes appropriate, and the string material is sewn onto a sewn object. A ruffling sewing mechanism N includes: a bearing member for bearing the string material A guided by the guide mechanism; and a forward member 35 for being displaced relative to the bearing member and forwarding the string material born by the bearing member to a needle base position. The string material is guided to the needle base position in a state that the string material is folded by forwarding operation of the forwarding member 35.