Desalination has become one of the main methods for producing drinking water, especially in the countries without safe drinking water sources (for example the Midwest countries). However, there is an increasing demand for such a water source also in other countries due to increasing demand for drinking water, lower cost of desalination and advances in technology. This thesis describes different technologies, their strengths and weaknesses, environmental impact and presents a study of a desalination device set-up to supply a nearby city. The study contains a selection of the size of the device depending on the needs of the city and estimates the cost of such a device (investment, operation, maintenance). In conclusion, calculation results are given with comment on calculation results obtained.