Patent ID: 7748788

Claim:
A ventilation portion structure provided in a surface of a seat which is in contact with a user, comprising: an epidermal material which has a notch portion for forming a ventilation portion and in which the edge of the notch portion is folded back toward the rear surface thereof; a ventilation bottom material disposed at the rear surface of the notch portion of the epidermal material to form a bottom surface of the ventilation portion; and a gusset material interposed between the folded edge of the epidermal material and the bottom material in a folded state such that a fold of the gusset material is directed to an inner circumference of the notch portion, and the edge of the epidermal material and the bottom material are connected to each other through the gusset material, wherein the gusset material is applied as a single gusset material, the folded edge of the epidermal material and one folded portion of the gusset material are sewed to each other, and the bottom material and another folded portion of the gusset material are sewed to each other.