It is intended to improve texture of a decoration using a stitch line while improving workability in sewing for forming the stitch line at a skin material, to promote manufacturing efficiency as compared to formation of a stepped shape only by sewing, and to reduce the number of steps. A skin material is used for a conveyance seat, and is molded using a die. The skin material includes a linearly-extending stepped portion having a stepped shape transferred from the die, and a stitch line sewn along the stepped portion. The stepped portion serves as a guide upon formation of the stitch line.