To provide an illumination method, an illumination optical apparatus, and an exposure equipment capable of maintaining compatibility concerning a light intensity distribution as needed, when an optical element whose configuration is different from that of an optical element used up to the present is used.

The illumination method includes: illuminating a first surface to be illuminated with light traveling through a diffractive optical element which determines a light intensity distribution at a first illumination pupil plane; measuring the light intensity distribution of the first illumination pupil plane; storing the measurement result as the first light intensity distribution; and illuminating a second surface to be illuminated with light travelling through a spatial light modulator 13 which can set a light intensity distribution at a second illumination pupil plane 22P at a distribution almost the same as the first light intensity distribution.