A light source apparatus comprises a main body, a plurality of light source modules and a processor. The main body includes a plurality of configuration areas distributed on a surface of the main body. The plurality of configuration areas is oriented towards different directions, respectively. The plurality of light source modules is located in the plurality of configuration areas, respectively. Each of the plurality of light source modules includes a circuit substrate and an ultraviolet emitting device. The processor is electrically connected to the plurality of light source modules. The processor is adapted to drive the ultraviolet emitting device of each of the plurality of light source modules. A method of using a light source apparatus is also provided.