To obtain the subject product capable of fitting the body and expressing a silhouette along a body without appearing to be fat when wearing the product by sewing a gusset in a rhombic shape, etc., having nonfraying edges in a specific site.

Nonfraying edges of straight-line parts 4 and 4 are formed in underarm parts AB in an armhole part 3 of a front and a back bodies 1 and 2 by decreasing stitches. Nonfraying edges of straight-line parts 7 and 7 are formed in both underarm parts AC in a sleeve cap 6 of a sleeve part 5 by similarly decreasing the stitches. A gusset 8 in a rhombic shape, etc., having the nonfraying edges is formed by increasing and decreasing the stitches and then sewn together by linking thereof to the underarm parts AB and AC in the armhole part 3 of the sewn front and back bodies 1 and 2 with the lower part of the sleeve cap 6 of the sleeve part 5.