A multistage membrane distillation apparatus, comprising: a plurality of multistage membrane distillation modules (500, 600), the modules being configured to be flowed through by a liquid to be concentrated and configured to be provided in parallel with steam, wherein: each module (500, 600) comprises a plurality of serial condensation/evaporation stages (50, 60) configured to be flowed through by the liquid to be concentrated, each condensation/evaporation stage (50, 60) comprises a plurality of parallel condensation/evaporation elements (101, 102) configured to be flowed through by the liquid to be concentrated, and each condensation/ evaporation element comprises at least one condensation unit and at least one evaporation unit, wherein steam outlet passages of the evaporation units of a preceding stage are connected to steam inlet passages of the condensation units of a successive stage for forming a steam channel providing steam from the preceding stage to the successive stage, wherein each of the condensation units comprises a first steam space at least partly limited by a condensation wall; each of the respective evaporation units comprises a second steam space at least partly limited by a steam-permeable, liquid tight membrane wall; and at least one flow channel for the liquid to be concentrated is provided between a condensation unit and an adjacent evaporation unit such that the liquid inside the flow channel is heated via the condensation wall and the steam arising from the liquid to be concentrated moves through the membrane wall into the second steam space, the apparatus being characterized by further comprising at least one of: a centralized heating stage configured to generate steam and to provide the steam to each of the modules in parallel, and a centralized condensation stage configured to receive steam from each of the modules in parallel and to condensate the steam. each module (500, 600) comprises a plurality of serial condensation/evaporation stages (50, 60) configured to be flowed through by the liquid to be concentrated, each condensation/evaporation stage (50, 60) comprises a plurality of parallel condensation/evaporation elements (101, 102) configured to be flowed through by the liquid to be concentrated, and each condensation/ evaporation element comprises at least one condensation unit and at least one evaporation unit, wherein steam outlet passages of the evaporation units of a preceding stage are connected to steam inlet passages of the condensation units of a successive stage for forming a steam channel providing steam from the preceding stage to the successive stage, wherein each of the condensation units comprises a first steam space at least partly limited by a condensation wall; each of the respective evaporation units comprises a second steam space at least partly limited by a steam-permeable, liquid tight membrane wall; and at least one flow channel for the liquid to be concentrated is provided between a condensation unit and an adjacent evaporation unit such that the liquid inside the flow channel is heated via the condensation wall and the steam arising from the liquid to be concentrated moves through the membrane wall into the second steam space, the apparatus being characterized by further comprising at least one of: a centralized heating stage configured to generate steam and to provide the steam to each of the modules in parallel, and a centralized condensation stage configured to receive steam from each of the modules in parallel and to condensate the steam. a centralized heating stage configured to generate steam and to provide the steam to each of the modules in parallel, and a centralized condensation stage configured to receive steam from each of the modules in parallel and to condensate the steam.