Screen device in which two beams (1, 2) in the mounted state of the screen device are mutually coupled with the aid of: —a first coupling piece (3), comprising a first mounting cavity (4) for the fitting herein of a first part of the first beam (1); and a second mounting cavity (5) for the fitting herein of a first part of the second beam (2); —and a second coupling piece (6), comprising a first mounting cavity (7) for the fitting herein of a second part of the first beam (1), extending opposite the first part; and a second mounting cavity (8) for the fitting herein of a second part of the second beam (2), extending opposite the first part.