NOVELTY - The device comprises a coating chamber with coating areas, a device for transporting flat substrates in transport direction of the coating chamber and supporting the substrates in the chamber, a coating device separating gaseous coating material from the substrates, a suction device and an exhaust unit extending parallel to the coating device, a pump connected in axial extension of the suction device for generating negative pressure inside the suction device with respect to the internal pressure of the coating chamber, and a set of suction ports formed on the suction device.    USE - The device is useful for movement of gas in a vacuum coating equipment (claimed) that is useful for coating a substrate with thin layers of element or compounds in manufacturing solar and semiconductor devices.    ADVANTAGE - The device allows defined movement of gas in the coating chamber to form thick homogeneous layers uniformly on the substrate in a controllable manner without flow differences.    DETAILED DESCRIPTION - The device comprises a coating chamber with coating areas, a device for transporting flat substrates (3) in transport direction of the coating chamber and supporting the substrates in the chamber, a coating device separating gaseous coating material from the substrates, a suction device and an exhaust unit extending parallel to the coating device, a pump connected in axial extension of the suction device (1) for generating negative pressure inside the suction device with respect to the internal pressure of the coating chamber, a set of suction ports formed on the suction device, and two axial regions formed in the exhaust unit with adjustable suction characteristics, where the axial regions are separated from each other, and a length of the coating device is equal to a width of the substrate. A diffuser is provided inside the suction device. The diffuser is a labyrinth having pressure loss in a linear direction of the suction device, which is very smaller than the pressure loss in a circumferential direction of the device. An inner pipe (11) is placed inside the suction device. A set of intake openings (111) is formed along a length of the pump, where the openings face away from the suction ports. A width of the intake openings varies from each other. The inner pipe is twisted along the entire length of the pipe. The inner pipe is rigidly connected with an outer pipe (12) by an intermediate wall. The suction device and the inner pipe are divided by a partition wall. The partition wall is arranged centrally and/or axially between the suction device and the inner pipe. The inner tube is divided into two inner pipe sections when the partition wall is fixed axially. Flow guide plates are arranged outside of the suction device to axially move the suction device. The inner pipe comprises flow guide plates at the outer side for influence of the fluid flow passing through the intake opening, and a rotating drive rotating completely or partially in the inner pipe during processing of the substrate about the longitudinal axis of the pipe.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of a gas suction device.    Gas suction device (1)    Substrates (3)    Inner pipe (11)    Outer pipe (12)    Intake openings. (111)