An illumination light generation apparatus (110; 120; 130) comprising: a light source unit including first and second light source groups that radiate a plurality of light beams, respectively, the first and second light source groups facing each other; and an emission unit that emits a composite light beam in a predetermined direction (Px) including a first reflection part facing the first light source group that reflects the plurality of light beams radiated from the first light source group, and a second reflection part that faces the first reflection part (31 A), the second reflection part faces the second light source group and is configured to reflect the plurality of light beams radiated from the second light source group to the first reflection part; and further comprising: a retaining unit that retains the light source unit; wherein each of the first and second light source groups (21A; 21B) include a plurality of light sources from which the plurality of light beams are radiated, and wherein the retaining unit is configured to retain the light source unit, so that the plurality of light sources are arranged in a substantially circular shape or a polygonal shape, characterized in that the retaining unit retains the first and second reflection parts (31A, 31B) within a perimeter defined by the second and first light source groups (21B, 21A) respectively and the emission part further comprises an emission part facing the first reflection part that reflects the plurality of light beams reflected from the first reflection part and the plurality of light beams radiated from the second light source group (2 1 B); wherein the emission part generates the composite light beam by reflecting the plurality of light beams radiated from the first light source group and the plurality of light beams radiated from the second light source group in the predetermined direction, and the first reflection part is configured to reflect the plurality of light beams reflected from the second reflection part to the emission part. a light source unit including first and second light source groups that radiate a plurality of light beams, respectively, the first and second light source groups facing each other; and an emission unit that emits a composite light beam in a predetermined direction (Px) including a first reflection part facing the first light source group that reflects the plurality of light beams radiated from the first light source group, and a second reflection part that faces the first reflection part (31 A), the second reflection part faces the second light source group and is configured to reflect the plurality of light beams radiated from the second light source group to the first reflection part; and further comprising: a retaining unit that retains the light source unit; wherein each of the first and second light source groups (21A; 21B) include a plurality of light sources from which the plurality of light beams are radiated, and wherein the retaining unit is configured to retain the light source unit, so that the plurality of light sources are arranged in a substantially circular shape or a polygonal shape, a retaining unit that retains the light source unit; wherein each of the first and second light source groups (21A; 21B) include a plurality of light sources from which the plurality of light beams are radiated, and wherein the retaining unit is configured to retain the light source unit, so that the plurality of light sources are arranged in a substantially circular shape or a polygonal shape,