Chair

A chair comprising:

• a leg erected on a floor surface;
• a seat arranged above the leg;
• a backrest being arranged behind the leg and including a pressure receiving surface;
• and
• a support mechanism arranged below the seat to be interposed between the leg and the seat and configured to movably support the seat in a front-rear or left-right direction along a predetermined trajectory and to downwardly incline a tip side of the seat in a movement direction in accordance with a movement of the seat from a predetermined reference position, wherein
• the support mechanism including a return-force generation unit configured to generate, in accordance with an amount of movement, a return force in a direction in which the seat moved from the reference position in the front-rear or left-right direction is returned to the reference position, and being configured to movably support the backrest in the left-right direction together with a movement of the seat in the left-right direction, wherein
• at least one of the seat or the backrest includes a main body unit, and an amplification element attached to the main body unit and configured to further amplify a movement operation of the main body unit in the left-right direction among movement operations of the main body unit.