At the moment the legal position of Austria concerning the magnesia industry is not clear at all. In future it is planned to admit the magnesia industry to the BAT-document of Cement and Lime Facturing Industry. At the same time this will mean, that stricter emission values have to be met. This master thesis aims to show the different possibilities of offgas-treatment. The first part contains the basis of Magnesia production, Magnesia production in Hochfilzen as well as the results of former emission measuring. The following part sums up which methods of offgas-treatment are generally known in literature, to reduce the amounts of dust, nitrous gases, sulphur dioxide and carbon monoxide. As the result of the thesis a matrix shows all possibilities how the different methods can be combined. The matrix is based on the realization, that the existing RCE-scrubber system is the best solution to reduce the SO2-emissions. There is no other process which reaches better emission values and it is the only one which makes use of the existence of MgO dust in the Magnesia production. Apart from the existing CO-reburning there is no method known to reduce the CO-emissions and can be applied in Magnesia industry without great adaptions. To minimize the NOx-emissions common procedures like SCR or SNCR, as they are used for example in the cement industry, can not be used in Magnesia industry. One option is the primary measure of air-staging. The recommendation of dedusting is to remove the existing cyclone system and replace it by electrostatic precipitators, fabric filters or special wet dust extraction systems.