Abstract: Described are a process and an apparatus for the aftercondensation of polycondensates, wherein moist and amorphous polymer in a granular or powderous form is continuously introduced from above into a single reactor. The granulate flows downward under gravity, with a hot gas being caused to flow in counter-current relation thereto. The reactor is formed as a continuous shaft or column which has positioned in the upper portion thereof an agitating element acting to prevent agglutination of the granulate. The granulate is crystallized and pre-dried in the upper portion of the shaft or column. In a further (subsequent) portion of the shaft or column, drying and aftercondensation take place without separation from the remainder of the shaft or column.