To dispense with the sewing with maintaining a stretched state of a strip-like elastic body by a worker to reduce worker's fatigue caused by repetition of the sewing when sewing the elastic body on an apparel body hem or the like with the stretched elastic body and the apparel body hem fitted after the stretched elastic body is inserted into the apparel body hem sewn or folded back in an elongated rectangular shape.

This sewn object retainer comprises a pair of retention members capable of respectively retaining both end parts of the strip-like sewn object, a retainer base material allowing installation of at least one of the retention members with the retention member movable in the contact/separation direction of both the retention members, and a fixing means capable of fixing the movably installed retention member at an arbitrary position within the movable area. By use of the sewn object retainer, the strip-like sewn object is inserted into the sewn object having at least the rectangular shape with both the short sides closed, and the strip-like sewn object and the sewn object having the rectangular shape are simultaneously retained and sewn.