Chair

A chair comprising:

• a support structure;
• a backrest that is rotatably supported by the support structure around an pivot axis in a chair widthwise direction and that is displaceable in a forward/rearward direction between a standing state and an inclined state;
• a seat that has a front side supported part movably supported in the forward/rearward direction relative to a front portion of the support structure and a rear side supported part supported at a position above the pivot axis, and that is displaceable in the forward/rearward direction depending on displacement of the backrest with respect to the support structure;
• and
• a spring member that is provided in a state compressed between the seat and the backrest or between the seat and the support structure and that is configured to bias the backrest in a direction of returning to the standing state,
• wherein the spring member is disposed so that a biasing direction is in the forward/rearward direction, and includes a front side engagement portion disposed on a front portion of the spring and a rear side engagement portion disposed on a rear portion of the spring,
• the seat includes a front side spring receiving portion engaged with the front side engagement portion,
• the backrest or the support structure includes a rear side spring receiving portion configured to engage with the rear side engagement portion and an adjustment portion configured to adjust a position of the rear side engagement portion in an upward/downward direction together with the rear side spring receiving portion, and
• an upper limit position of the rear side engagement portion of the spring member adjusted by the adjustment portion is located above the pivot axis.