A casing structure for a fluid flow machine, in particular for a gas turbine or an aircraft engine, including an outer casing wall and an inner casing wall, which annularly surround a flow channel of the fluid flow machine and are spaced apart in a radial direction with respect to the flow channel. At least one cavity is formed between the inner and outer casing walls. The cavity is axially divided into at least two regions which are separated from each other by an axial seal in such a way that different pressure conditions are created according to the axial position of these regions, which different pressure conditions correspond to the pressure conditions in the flow channel. A corresponding fluid flow machine such as, for example, an aircraft engine.