The device for opening and closing a movable part of a furniture unit comprises a body (108), associated with a fixed part of the furniture unit (116), for supporting a slider (3) reversibly sliding along a sliding axis (100) in contrast and due to the action of a first spring (5), the slider being engageable with a drawing device provided on a drawing element (105) slidable in the direction of the sliding axis with an integral or reversibly couplable connection to the movable part (103) of the furniture unit, the supporting body comprising a first displacement device suitable for moving the drawing device so as to release the drawing device and the slider from their mutual engagement, an elastically yielding stop element against which the drawing element abuts directly or indirectly before engaging with the drawing device in the first displacement device.