Device for overturning a box closed by a lid so that the lid becomes the base of the box, comprising a fixed frame, means for gripping the box, means for approaching/removing the gripping means with respect to each other, means for raising/lowering the gripping means and means for rotating the gripping means, the means for raising/lowering and the means for rotating integrally moving the gripping means, wherein said gripping means comprise combs, characterized in that the raising/lowering means comprise a first movable plate, a pneumatic cylinder integral with the fixed frame, a stem controlled for vertical movement by the cylinder, wherein the first movable plate is integral with the stem, the means for approaching/removing the combs comprise a wheel which is provided with two arms at the ends of which cranks are rotatably mounted at their first ends, the second ends of the cranks being rotatably fixed to respective combs slidingly associated with a second movable plate of the overturning device by means of runners sliding along guides, wherein the second movable plate is rotatable, wherein the rotation means comprise two gear wheels (52, 53) connected by a belt, wherein a first motor is able to control the first gear wheel, while a second motor is able to control the rotation of the wheel independently of the rotation of said second movable plate, wherein the first movable plate rotatably supports the two gear wheels (52, 53), the first motor and the second motor, the second movable plate is integral with the second gear wheel, the rotation of the wheel determining the approach/removal of the combs with respect to each other, the actuation of the gear wheels (52, 53) determining the rotation of the second plate and therefore of the combs, the cylinder determining the vertical movement of the second plate and therefore of both combs. the raising/lowering means comprise a first movable plate, a pneumatic cylinder integral with the fixed frame, a stem controlled for vertical movement by the cylinder, wherein the first movable plate is integral with the stem, the means for approaching/removing the combs comprise a wheel which is provided with two arms at the ends of which cranks are rotatably mounted at their first ends, the second ends of the cranks being rotatably fixed to respective combs slidingly associated with a second movable plate of the overturning device by means of runners sliding along guides, wherein the second movable plate is rotatable, wherein the rotation means comprise two gear wheels (52, 53) connected by a belt, wherein a first motor is able to control the first gear wheel, while a second motor is able to control the rotation of the wheel independently of the rotation of said second movable plate, wherein the first movable plate rotatably supports the two gear wheels (52, 53), the first motor and the second motor, the second movable plate is integral with the second gear wheel, the rotation of the wheel determining the approach/removal of the combs with respect to each other, the actuation of the gear wheels (52, 53) determining the rotation of the second plate and therefore of the combs, the cylinder determining the vertical movement of the second plate and therefore of both combs.