Chair with return force mechanism

A chair configured to be movable in the front-back direction and in a left-right direction and having a reference position located midway in a front-back direction and in a left-right direction in a movable range of a seat, the chair comprising:

• a first return force generation mechanism configured to generate a return force in a direction to return the seat moved from the reference position in the front-back direction to the reference position;
• and
• a second return force generation mechanism configured to generate a return force in a direction to return the seat moved from the reference position in the left-right direction to the reference position,
• wherein the first return force generation mechanism comprises an elastic member configured to increase the return force in the direction to return the seat to the reference position as an amount of movement of the seat from the reference position increases,
• wherein the second return force generation mechanism is configured to shift the center of gravity of the seat upward in accordance with the movement of the seat from the reference position,
• wherein regardless of whether the seat moves front, back, left or right, a movement end of the seat inclines downward in accordance with the amount of movement of the seat.