Abstract: A sewage treatment plant for the purification of waste water includes a chamber container (1) divided by partitions (4) into different sections (6, 7, 8) for pretreatment, biological treatment, chemical treatment, intermediate or retreatment of waste water, each section (6, 7, 8) having several chambers (6a through f, 7a through f, 8a through f) separated from one another by dividing walls (4, 5), chambers (6a through f, 7a through f, 8a through f) being linkable, with regard to inflow technique, in any pre-selectable association depending on the quantity and type of waste water to be treated, and at least one installation for removal of deposited treatment sludge in each of the areas for pretreatment, intermediate treatment and retreatment.