The roof window comprises a stationary frame (1) adapted to be built into a structure and having a top member (12), two side members (13, 14) and a bottom member (11), and defining a frame plane, a sash (2) having a top member (22), two side members (23, 24) and a bottom member (21), and carrying a pane (3) and defining a sash plane in parallel with the pane, an intermediate frame (4), and at least one first hinge connection (15) for connecting the sash (2) and the intermediate frame (4) to the stationary frame (1). Releasable locking means (16) for releasing the first hinge connection (15) are provided, and at least one second hinge connection (25) for connecting the sash (2) to the intermediate frame (4), as well as operating means (8) for opening and closing the sash relative to the frame. In order to provide a substantially weather-proof transition between the roof window and the surroundings, a first set of cover elements (100) is provided on the stationary frame and a second set of cover elements (200) provided on the sash. The second set of cover elements includes a top sash cover element (200) and the first set of cover elements includes a top frame cover element (100). The top sash cover element overlaps the top frame cover element to a maximum opening angle when the sash is rotated in a first direction relative to the frame plane, but is releasable from the overlap to allow a rotation of the sash in a second direction opposite the first direction.