A compressor compresses air to produce compressed air. A mixture of fuel and the compressed air is combusted in a combustor to produce combustion gas. The combustion gas is supplied to a turbine to obtain rotational power. High-temperature gas accumulated in a space partitioned by an exhaust-side bearing portion that rotatably supports a turbine shaft and an exhaust diffuser is discharged through an exhaust gas passage. The high-temperature gas is sucked into the exhaust gas passage by exhaust gas flowing in the exhaust diffuser.