Adjustment mechanism, optical system, exposure apparatus, and article manufacturing method

An adjustment mechanism that adjusts at least one of a position and a shape of an optical element, comprising:

• a deformation portion;
• and
• a driver configured to apply a force to the optical element via the deformation portion,
• wherein the deformation portion includes
• a first plate including a first part and a second part,
• a second plate arranged between the first plate and the optical element, including a third part and a fourth part, and configured to transmit a force to the optical element,
• a first connection portion configured to connect the first part and the third part, and
• a second connection portion configured to connect the second part and the fourth part,
• an interval between the first part and the second part is smaller than an interval between the third part and the fourth part, and
• the driver applies a force between the first part and the second part of the first plate.