A post-processing apparatus of a solar cell carries out a post-processing operation including a main period for heat-treating a solar cell including a semiconductor substrate while providing light to the solar cell. The post-processing apparatus includes a main section to carry out the main period. The main section includes a first heat source unit to provide heat to the semiconductor substrate and a light source unit to provide light to the semiconductor substrate. The first heat source unit and the light source unit are positioned in the main section. The light source unit includes a light source constituted by a plasma lighting system (PLS).