To provide a lighting optical device which adjusts pupil intensity distribution without replacement of an optical member.

An optical unit includes: a first optical path where a spatial modulation element having a plurality of optical elements arranged two-dimensionally and controlled individually may be arranged; a second optical path having a mechanism for insertion of an angular distribution providing element having a predetermined fixed pattern on a surface thereof; and a third element being an optical path of light having travelled through both of the first optical path and the second optical path. When the angular distribution providing element is inserted in the second optical path, an angular distribution is given to exiting light based on light incident to the angular distribution providing element.