A greenhouse (1) comprises a roof structure including a transparent cover supported by a plurality of parallel longitudinal sections (6) and a transparent foil (7) which extends at a distance from the cover (2) below the cover (2). Opposite side edges of the foil (7) are mounted to respective transverse sections (4, 8) which are located at a distance from each other and which are each connected to at least two longitudinal sections (4, 8) and which extend in transverse direction of the longitudinal sections (6). At least one of the transverse sections (8) is displaceable in longitudinal direction of the longitudinal sections (6) so as to be able to change the mutual distance of the transverse sections (4, 8).
