Seat

A seat comprising:

• a seat frame;
• and
• a cushion material including a three-dimensional knitted fabric supported by the seat frame and formed by joining, with connecting threads, a pair of ground knit fabrics which are disposed so as to be separated from one another, wherein
• the cushion material includes a first region whose elastic compliance when a reaction force is applied to an extending side of the cushion material when an occupant is seated on the seat is adapted to be substantially equivalent to an elastic compliance of a portion of the occupant's body pressing the cushion material and which first region is adapted to be positioned at a predetermined region including a seat portion which contacts a tuber ishiadicum bottom portion of the seated occupant, a second region whose elastic compliance is larger than the elastic compliance of the first region and which is positioned in the vicinity of a front edge portion of the seat portion, and a third region whose elastic compliance is smaller than the elastic compliance of the first region and which is adapted to be positioned at a position corresponding to a vicinity of a pelvis front portion of the seat occupant.