Exhaust gas diffusor for a gas turbine

The exhaust gas diffuser (20) has a flow channel (26) that is extended in axial direction and is formed radially outward from exterior wall (21). A hub structure (24) is provided in the center of the flow channel. A partial flow-through wall (30) is formed in the hub structure. A cavity is formed surrounding the flow-through wall. The holes are evenly distributed in the flow-through wall. The permeability of the flow-through wall is adjusted according to cross sectional area of the holes.