In the present invention an attachment support (27) and an air labyrinth (28) arranged between a lubricating oil head tank (24) storing lubricating oil and a compressor impeller (14) separate the compressor impeller (14) and the lubricating oil head tank (24), and an attachment support flange (34) of the attachment support (27) is arranged closer to the compressor impeller (14) than an air labyrinth flange (36) of the air labyrinth (28). With this exhaust turbine supercharger the attachment support (27) can easily be detached and attached with respect to a bearing base main body casing (21) while the air labyrinth (28) remains installed on the bearing base main body casing (21), thus improving maintainability.