This article addresses advanced methods of wastewater treatment, which presents an urgent global problem. The use of membranes or so-called membrane bioreactors (MBR) at treatment facilities comprises an efficient method of wastewater treatment. The characteristics of membrane designs along with their practical advantages and disadvantages are considered. Examples of using MBR at wastewater treatment plants in Germany, Italy and Sweden are examined. A recently developed MBR technology based on filtration through micro- or ultrafiltration membranes is gaining in popularity. In such technologies, the high quality of treated water is achieved due to the MBR design, which increases both the concentration of activated sludge in the bioreactor and its filtering capacity. Over 100 years of contemporary residential and industrial wastewater treatment, no other implemented technology has exhibited as many positive effects. Due to the wide range of available membranes and modules, suitable systems can be found for almost any type of water treatment application. In addition, these membranes are compact, which becomes an advantage when clearing areas for new construction or when the expansion of a wastewater treatment plant is limited.