The invention refers to a modular and adjustable roofing device for greenhouses allowing self-adjustment according to the weather conditions for optimizing the performance of the crops inside the greenhouse. The device comprises a main self-adjusting supporting axis and, at least, one secondary supporting axis, a concave roofing with an impermeable and folding cover, a sensor detecting the weather conditions of the surroundings and a system collecting rain water in the roofing, where the sensor detects the weather conditions and allows opening and closing the impermeable cover of the device roofing and adjusting the height of the supporting axes for providing the crops arranged inside the greenhouse with the optimum conditions.
