A gas turbine having a turbine casing, an outer and inner casing part between which a hot gas flows. An annular duct is formed between the outer casing part and the turbine casing to accommodate a cooling fluid. An exhaust gas casing is positioned downstream in the flow direction of the hot gas. A bearing system for a rotor has bearing struts arranged around the circumference which extend from a shaft bearing to an outer casing and, in the hot gas path of an exhaust gas diffuser arranged in the exhaust gas casing are shielded by another strut set which surrounds the bearing struts and is hollow to support the diffuser, wherein, to center the turbine and the exhaust gas casing, these are connected to one another via a fit wherein the turbine and the exhaust gas casing can be supplied with cooling air independently of one another.