The problem of pollution by wastewater in Indonesia, both domestic wastewater and industrial wastewater, is still a serious problem. Every business or activity that produces domestic wastewater is required to treat the wastewater produced (Daya, 2020). Wastewater from big cities and medium cities, including in Yogyakarta City, still needs the right method to handle it. RBC (Rotating Biological Contactor) is one of the biological processing technologies. Management with this RBC utilizes microorganisms by using biofilms as a place to grow and attach these microorganisms to be able to reduce organic parameters such as BOD, COD, TSS, pH, ammonia levels, oil & fat (LHK Regulation number 68 of 2016) concerning domestic wastewater quality standards. Rotating Biological Contactor abbreviated as RBC is an adaptation of the wastewater treatment process with attached growth. Earthenware used to purify water is earthenware that has the ability to absorb water, consisting of a group of soft earthenware (both white and red). Items that absorb water from the soft earthenware group, consisting of kaolin, clay, and kwarsa materials (Hasnani, 2013). The purpose of this study is to design the Application of Rotating Biological Contactor (RBC) Technology with Kasongan Pottery Waste Filter Media to treat Wastewater. Measuring the parameters of BOD, COD, TSS, pH, ammonia, oil & fat levels and Making Prototype Applications of Rotating Biological Contactor (RBC) Technology with Kasongan Pottery Waste Filter Media to treat wastewater and make tools that can be used by the community to treat wastewater in groups. The Research Method is Quasi-experimental research. Quasi-experimental research is an experimental activity (experiment) that aims to obtain information that is an estimate of the information that can be obtained with an actual experiment under circumstances that is impossible to control or manipulate all variables. The stage is to design the design of the RBC Technology Application tool with the fiteration media of kasongan earthenware waste, assembling the tool and testing the function of the tool by treating wastewater. Testing data for the parameters of BOD, COD, TSS, pH, ammonia levels, oil & fat wastewater that the sample is taken from wastewater before being processed as a Pre test and flowing through a series of RBC tools to be carried out further wastewater treatment as a post test. The output of this study entitled Application of RBC Technology with kasongan earthenware waste filter media is a prototype stored in the Appropriate Technology Laboratory, for teaching materials to learn practical learning of the Liquid Waste Treatment course. Indexed national journals and textbooks that can be used for students of the D-III Sanitation Study Program in semester III and IV students in semester V and VI for the Applied Undergraduate Study Program. In the final stage, the additional research output is the Application of RBC Technology with casongan earthenware waste filter media on wastewater treatment with the result that it can reduce the parameters of COD 48.22%, BOD 45.27%, Ammonia 50.54%, TSS 62.51%, oil fat content 62.32% and pH from 7.13 to 7.04. [ABSTRACT FROM AUTHOR]