The exhaust turbocharger (1) has an external housing (2), an interior housing (3) and a turbine wheel (11). The external housing is connected with a bearing flange (14) and the interior housing is coupled in a form-lock manner with the bearing flange. A collar (17) is formed at the interior housing at an inner lying edge (16) of the bearing flange in a direction of a turbine wheel rotational axis (13) in sections to a plant.
