A turbine housing is provided with an inner pipe forming a spiral-shaped exhaust gas flow path, an exhaust-air-inlet-side flange serving as an exhaust gas inlet to the inner pipe, and an outer pipe that, together with the exhaust-air-inlet-side flange, covers and seals the inner pipe. The outer pipe has an opening through which the washing fluid can pass through and a closing member that closes the opening, and a space through which the washing fluid can pass through is formed between the inner pipe and the exhaust-air-inlet-side flange.