The rural areas in the Gaza Strip suffer from the problem of sanitation and organic waste as well as electricity and cooking fuel. In this thesis, the biogas plant was designed to solve those problems based on the fixed dome plant design as shown in Figure 3 and4. Therefore, the efficiency and selectivity was good for biogas plant which is easy for the local people disposal of organic waste and wastewater as well as self-sufficiency of biogas for cooking and electricity for the family. The sediments from the biogas plant are also used as fertilizers in agriculture. Thus it is possible to know the amount of biogas production, the cost of biogas, the amount of fertilizer, the cost of fertilizers and the amount of disposal of organic waste and wastewater. The calculation shows that the size of digester which is equal to 12 cubic meters as shown in figure 4.The construction is cost of $ 930 as shown in Table 2. Through the results will be disposed of organic waste, wastewater and manure are about 48 kilograms per day for the family. The Biogas is produced 0.5 tons of biogas is estimated about $ 100 in rural areas in the Gaza Strip. It is also produced fertilizers equivalent of $ 113 per month. So the results and calculations are clear that the rural family is self-sufficient of biogas, the dispose of organic waste and wastewater and agricultural growth by the fertilizers from the biogas plant.