The invention relates to a device (10) for applying a thin coat consisting of a fluid coating medium on the curved surface (12) of a screen of a cathode-ray tube (11). Said device comprises a rotary table (20) that can be driven rotationally. The rotary table also includes a location (30) for the object (11) to be coated to fix said object in such a way that it cannot rotate and a processing tank (50) surrounding the location (30) and the rotary table (20) that is locked to prevent turning. A first annular gap is provided between the spray ring (60) and the upper part (51) of the processing tank (50) while the location (30) is fitted with a suction cone (32). A second annular gap (37) is formed between said cone and an outer wall of the processing tank (50). An annealing chamber (36) is formed inside said second annular gap. A laminar flow (A) is directed towards the spray ring (60) or the upper part of the processing tank (50). The bottom (54) of the processing tank (50) is connected to a suction device (B).