Anaerobic treatment methods are becoming increasingly popular for the treatment of various wastewaters. Applicable of anaerobic treatment technology municipal waste water is significant for developing country like India because of high energy savings and low capital and OM costs. Among the anaerobic processes upflow Anaerobic sludge Blanket (UASB) reactor has been widely used to treat variety of industrial and domestic waste waters all over the world. Its working and design considerations are considered in this seminars.