Sunscreen device with adjustable and openable slats, for openings and for making coverings, comprising at least a plurality of elongated slat elements, movable at least between opened and closed conditions and each having two smaller transversal sides and two longitudinal main sides first and second and having an axle parallel to these last longitudinal main sides (6, 7) and the ends of each axle protrude from said transversal sides and longitudinally slide along respective first sites for sliding each obtained along the longitudinal extension of a side guide element perpendicular to the slat elements and fixable to a respective side of the opening and covering; each axle is connected to at least one distance adjustment member which regulates the distance between said axles between a minimum value in the opened condition and a maximum value in the closed condition, where each slat element carries at least one respective arm element provided at its own free end of a slider element; said device is characterized in that it comprises at least a rotation member for the rotation, in the closed condition, of each slat element, around its own axle where such rotation member comprises a longitudinal track element parallel to said first lateral sites for sliding and comprises, for each slat member, a corresponding transversal track element where the transversal track elements are likewise inclined with respect to the longitudinal track element and placed at mutual distances equal to the maximum distance value in the closed condition between said axles, and said rotation member also comprises a set of switch elements each placed at the intersection between the longitudinal track element and a respective switch element and each provided with a corresponding swivelling track element rotating between a rotating condition in which it is aligned to the respective transversal track element and a sliding condition in which it is aligned with the longitudinal track element; said device also comprises translation actuator members connected to the rotation member for translating it parallel to the longitudinal track element and swivel actuator members connected to the switch elements to synchronously rotate the swivelling track elements between the rotating and sliding conditions; where each slider element of each slat element is assigned to slide in the respective swivelling track elements and transversal track elements for rotation of the respective slat element in the closed condition and along the longitudinal track element during the translation of the respective slat element between the closed condition and the opened condition and vice versa; in an operative and closed condition the slider elements of the slat elements slide along the transversal track elements and swivelling track elements as a result of the translation of the rotation member implemented by the translation actuator member and modify the angle of the respective slat elements by rotating them around the respective axles; when the slat elements form a predetermined value of the angle of rotation, the slider elements are in the swivelling track elements of the switch elements aligned with the transversal track elements and the actuation of the swivel actuator member aligns these swivelling track elements to the longitudinal track element allowing the sliding along the latter of the slider elements and allowing the distance adjustment member to translate the slat elements towards the opened condition.