A seat comprises a seat back including a back plate, a cushion member arranged on the side of a seating face of the back plate, a superficial skin member covering the cushion member from the side of the seating face. The back plate includes a back face portion, a ridged portion, and a flange portion. A fringe portion of the superficial skin member is overlapped to a back face of the flange portion to be joined to the flange portion. A staple cover covering the fringe portion of the superficial skin member and a portion of the superficial skin member arranged on an outer peripheral face of the seat back is provided. The superficial skin member is arranged nearer a seating face than an outer peripheral end of the staple cover and extends to the outside beyond the outer peripheral end of the staple cover.