The task of the invention is to realize an illumination apparatus which has a plurality of light source sections and reduces the brightness asymmetry and color asymmetry of light and can sufficiently obtain the imaging performance. The illumination apparatus (10) includes: a first light source section (1); a plurality of second light source sections (2a, 2b); and an optical axis conversion element (a quadrangular prism reflector (3)) which allows lights incident from the plurality of second light source sections (2a, 2b) to emit in such a way that exiting optical axes of the lights become approximately parallel to the illumination optical axis in positions close to the illumination optical axis (L).