A self-adjustable flow control device for controlling flow of a fluid from one space or area to another, useful at least for controlling flow of fluid, i.e. oil and/or gas including any water, from a reservoir and into a production pipe of a well in the oil and/or gas reservoir, which production pipe includes a lower drainage pipe, the device comprising: a basically flat disc, a holder device or arrangement and a recess, wherein the disc is provided in the recess, wherein the disc faces an outlet of an aperture or hole in the centre of the recess and is held in place in the recess by means of the holder device or arrangement, thereby allowing a said fluid to enter the control device through the central aperture or hole to flow towards and along the disc and out of the recess, and wherein the control device comprises a housing body in the form of a first disc-shaped body, the first disc-shaped body having an outer cylindrical segment and an inner cylindrical segment and having a side adjacent the central aperture or hole, wherein the control device comprises the holder device or arrangement in form of a second disc-shaped body with a cylindrical segment, wherein the basically flat disc is provided between the first and second disc-shaped bodies, wherein the first and second disc-shaped bodies are attached at a connection area such that the cylindrical segment of the second disc-shaped body fits within and protrudes in the opposite direction of the outer cylindrical segment of the first disc-shaped body, thereby space is provided between the first and second disc-shaped bodies to enable a said fluid to enter the control device through the central aperture or hole and flow towards and along the disc before flowing through a first annular opening formed between the inner cylindrical segment of the first disc-shaped body and the cylindrical segment of the second disc-shaped body and further out through a second annular opening formed between the cylindrical segment of the second disc-shaped body and the outer cylindrical segment of the first disc-shaped body. a basically flat disc, a holder device or arrangement and a recess, wherein the disc is provided in the recess, wherein the disc faces an outlet of an aperture or hole in the centre of the recess and is held in place in the recess by means of the holder device or arrangement, thereby allowing a said fluid to enter the control device through the central aperture or hole to flow towards and along the disc and out of the recess, and wherein the control device comprises a housing body in the form of a first disc-shaped body, the first disc-shaped body having an outer cylindrical segment and an inner cylindrical segment and having a side adjacent the central aperture or hole, wherein the control device comprises the holder device or arrangement in form of a second disc-shaped body with a cylindrical segment, wherein the basically flat disc is provided between the first and second disc-shaped bodies, wherein the first and second disc-shaped bodies are attached at a connection area such that the cylindrical segment of the second disc-shaped body fits within and protrudes in the opposite direction of the outer cylindrical segment of the first disc-shaped body, thereby space is provided between the first and second disc-shaped bodies to enable a said fluid to enter the control device through the central aperture or hole and flow towards and along the disc before flowing through a first annular opening formed between the inner cylindrical segment of the first disc-shaped body and the cylindrical segment of the second disc-shaped body and further out through a second annular opening formed between the cylindrical segment of the second disc-shaped body and the outer cylindrical segment of the first disc-shaped body.