A device for closing an opening, namely a door or a window, with a door or window leaf and at least one stop profile which co-operates with the door or window leaf in a largely positive-locking manner when the door or window is closed, wherein the narrow surface of the door or window leaf connecting the side edges (5, 6) of the side surfaces (3, 4) of the door or window leaf has at least two surfaces (7a, 7b) enclosing an angle (α), at least one of the two surfaces (7a, 7b) of the narrow surface of the door or window leaf forms an obtuse angle (β) with one of the side surfaces of the door or window leaf, the surface of the stop profile opposite the narrow surface of the door or window leaf in the closed state of the door or window has at least two surfaces (8a, 8b) enclosing an angle (χ), and at least one of the two surfaces (8a, 8b) of the stop profile forms an acute angle (δ) with a plane running parallel to one of the side surfaces (3, 4) of the door or window leaf when the door or window is closed, whereby when the door or window is closed the surface of the narrow surface of the door or window leaf enclosing an obtuse angle (β) with one of the side surfaces (3, 4) of the door or window leaf, and the surface of the stop profile enclosing an acute angle (δ) with a plane running parallel to one of the side surfaces (3, 4) of the door or window leaf when the door or window is closed run parallel to each other, characterised in that the stop profile can be arranged on the wall of a soffit or at least partially in the wall of a soffit and does not project beyond the soffit, and the door or window leaf and the stop profile each have at least one recess for a receiving body (12a, 12b) of a hinge for a concealed arrangement between the door or window leaf and the stop profile, and the device is preferably provided with a hinge for a concealed arrangement between the door or window leaf and the stop profile. a door or window leaf and at least one stop profile which co-operates with the door or window leaf in a largely positive-locking manner when the door or window is closed, wherein the narrow surface of the door or window leaf connecting the side edges (5, 6) of the side surfaces (3, 4) of the door or window leaf has at least two surfaces (7a, 7b) enclosing an angle (α), at least one of the two surfaces (7a, 7b) of the narrow surface of the door or window leaf forms an obtuse angle (β) with one of the side surfaces of the door or window leaf, the surface of the stop profile opposite the narrow surface of the door or window leaf in the closed state of the door or window has at least two surfaces (8a, 8b) enclosing an angle (χ), and at least one of the two surfaces (8a, 8b) of the stop profile forms an acute angle (δ) with a plane running parallel to one of the side surfaces (3, 4) of the door or window leaf when the door or window is closed, whereby when the door or window is closed the surface of the narrow surface of the door or window leaf enclosing an obtuse angle (β) with one of the side surfaces (3, 4) of the door or window leaf, and the surface of the stop profile enclosing an acute angle (δ) with a plane running parallel to one of the side surfaces (3, 4) of the door or window leaf when the door or window is closed the surface of the narrow surface of the door or window leaf enclosing an obtuse angle (β) with one of the side surfaces (3, 4) of the door or window leaf, and the surface of the stop profile enclosing an acute angle (δ) with a plane running parallel to one of the side surfaces (3, 4) of the door or window leaf when the door or window is closed run parallel to each other, characterised in that the stop profile can be arranged on the wall of a soffit or at least partially in the wall of a soffit and does not project beyond the soffit, and the door or window leaf and the stop profile each have at least one recess for a receiving body (12a, 12b) of a hinge for a concealed arrangement between the door or window leaf and the stop profile, and the device is preferably provided with a hinge for a concealed arrangement between the door or window leaf and the stop profile.