An extreme ultra-violet (EUV) light source apparatus includes a chamber body, a reflector, a plurality of gas injection holes, and a plurality of spitting suppression structures. The chamber body has an internal wall and an outer wall. The reflector is under the chamber body and is configured to focus EUV light. The plurality of gas injection holes extend from the outer wall of the chamber body to the internal wall of the chamber body. The plurality of spitting suppression structures are on the internal wall of the chamber body, and are configured to suppress spitting of debris. Each of the plurality of spitting suppression structures includes: a porous structure including a plurality of pores and a plurality of nodes; a plurality of fixing pins fixed to the internal wall of the chamber body, and spaced apart from the porous structure to an outer side of the porous structure; and a plurality of connection members each connected to a respective one of the nodes and a respective one of the fixing pins.