Patent ID: 7817249

Claim:
An exposure method, comprising: illuminating a first object formed with a pattern with a first light beam through an illumination optical system that changes an illumination condition of the first object to expose a second object with the first light beam through the first object and a projection optical system having a first optical member of which a first portion is irradiated with the first light beam and varies with the change of the illumination condition, and second optical members; irradiating a second portion of the first optical member of the projection optical system with a second light beam having a wavelength range different from that of the first light beam without passing through the second optical members of the projection optical system to correct optical characteristics of the projection optical system; and controlling a light quantity of the second light beam on the second portion for the correction of the optical characteristics by detecting the second light beam before the second light beam is incident on the second portion, wherein a position of the second portion is changed based on the first portion varying with the change of the illumination condition by the illumination optical system.