The device for automatic ventilation of the greenhouse is made in the form of a block-lining for the door or for another surface of the greenhouse, contains an outer sheet of polycarbonate, an inner sheet of polycarbonate, which is smaller in length and width than the outer sheet of polycarbonate. The inner sheet of polycarbonate and the outer sheet of polycarbonate have windows that are in turn arranged in rows along the entire surface of the outer sheet of polycarbonate and the inner sheet of polycarbonate and are designed so that when the inner polycarbonate sheet is moved downward, the windows open and, when displaced upwards, sheet polycarbonate and inner polycarbonate sheet. When the air temperature in the greenhouse rises, the working fluid in the hydraulic cylinder expands and drives the hydraulic cylinder piston, which through the rod of the hydraulic cylinder displaces the inner sheet of polycarbonate. The inner sheet of polycarbonate and the outer sheet of polycarbonate are connected by the fastening points of the outer sheet of polycarbonate and the inner sheet of polycarbonate, which are configured to move the inner polycarbonate sheet downwardly up through the slots therein. In addition, a compression spring is loosely attached to the hydraulic cylinder, which is fastened to the hydraulic cylinder fixed at one end to the attachment point to the movable sheet of a smaller polycarbonate size, and the other end to the rod assembly of the hydraulic cylinder to the outer sheet, thereby facilitating the displacement of the inner polycarbonate sheet and return to initial position. The inner sheet of polycarbonate and the outer sheet of polycarbonate are connected by the fastening points of the outer sheet of polycarbonate and the inner sheet of polycarbonate, which are configured to move the inner polycarbonate sheet downwardly up through the slots therein. In addition, a compression spring is loosely attached to the hydraulic cylinder, which is fastened to t
