An illumination apparatus includes a light source unit emitting coherent light in a first direction, a first light division unit, including a plurality of first slots, receiving the coherent light, each slot of the plurality of first slots reflecting a part of the coherent light in a second direction crossing the first direction, and a surface lighting plate including a plurality of second light division units, each light division unit of the plurality of second light division units includes a light guide through which light progresses, and each light division unit of the plurality of second light division units includes a plurality of second slots. Each slot of the plurality of second slots of each second light division unit reflects a part of the coherent light received from a corresponding slot of the plurality of first slots in a third direction which crosses the first and second directions.