A rotary machine include: a rotational shaft; an impeller mounted to the rotational shaft; an impeller housing accommodating the impeller; a bearing housing accommodating a bearing which supports the rotational shaft rotatably, the bearing housing being fastened to the impeller housing; and a fastening member fastening the impeller housing and the bearing housing in an axial direction of the rotational shaft. The impeller housing, the bearing housing, and the fastening member each includes a contact surface in a direction intersection with an axial direction of the rotational shaft. A thin-plate member formed separately from the impeller housing, the bearing housing, and the fastening member is interposed between at least two of the contact surfaces.