To provide a luminous flux splitting apparatus capable of guiding luminous flux having a desired intensity distribution to a plurality of spatial optical modulators without depending upon an intensity distribution of incident luminous flux.

The luminous flux splitting apparatus includes a spatial optical modulator (30) for splitting which includes a plurality of optical elements (30a) arrayed in a predetermined plane and individually controlled so as to split the incident luminous flux into two pieces of luminous flux and to guide first luminous flux along a first optical path and second luminous flux along a second optical path, and a driving section (30c) configured to drive the plurality of optical elements, and drives the driving section according to a control signal from a control section (CR). The spatial optical modulator for splitting is so controlled by the control section so that light passed through optical elements in a first group among the plurality of optical elements is guided along the first optical path and light passed through optical elements in a second group different from the first group among the plurality of optical elements is guided along the second optical path.