To provide an illumination optical device which illuminates an irradiated surface with light in a desired polarization state by adjusting the polarization distribution on an illumination pupil surface or the irradiated surface.

In order to adjust the polarization distribution of light on the pupil surface of an illumination optical apparatus which illuminates irradiated surfaces M, W based on the light from a light source 1, a polarization distribution adjustment member 9 is provided. The polarization distribution adjustment member has an optical rotary member arranged rotatably about the optical axis AX of the illumination optical apparatus, and imparting an amount of optical rotation dependent on the incident position to the incident light. The optical rotary member is formed of an optical material of optical rotation, and the thickness in the direction of optical axis changes in a predetermined direction orthogonal to the optical axis.