The Dynamic Ergodic Divertor (DED) is presently installed in TEXTOR. One of the aims is the study of the mitigation of the heat flux by rotating the divertor strike points. After an introduction into the theory of ergodization, the design of the DED is presented. The Chirikov parameter describing the level of ergodization reaches a level of up to four if the perturbation current is applied in an optimized way. Finally the rich physics options of the DED are discussed.