The present application relates to a distillation apparatus. According to the distillation apparatus of the present application, since a second compound, which has a relatively high boiling point between first and second compounds capable of forming an azeotropic mixture, is forced to flow into a supply port located at a part lower than a supply port of a first compound having a relatively low boiling point, the first compound can be separated in advance at the top of a first distillation column, and the amount of the first compound inside the flow discharged from the bottom of the first distillation column can be minimized, and thus the second compound can be separated in a high purity in accordance with the minimization of the movement path of the first compound.