Seat

A seat comprising:

• a skin which has a curved surface portion at least at a part thereof and in which an opening curved in a predetermined curved direction along the curved surface portion is formed at the curved surface portion;
• an elastically deformable plate-shaped reinforcing member which reinforces a peripheral area of the opening at the curved surface portion, the reinforcing member being disposed in a curved state along an inner surface of the curved surface portion;
• and
• a pressing member which covers the peripheral area of the opening in a pressing state from an outer surface of the curved surface portion,
• wherein the reinforcing member includes a main body portion which overlaps with the pressing member and sandwiches the skin in cooperation with the pressing member, and an extending portion which is connected to at least one side edge of the main body portion in a width direction orthogonal to the curved direction and extends in a range not overlapping with the pressing member,
• a slit is formed in the extending portion, and
• the slit extends in the curved direction such that a part of the extending portion on an outer side in the width direction is elastically deformable independently from the main body portion.