To provide a polishing device suppressing the rise of dust low and reducing the installation area.

This polishing device is provided with a polishing surface table 3 holding a polishing pad 2; a closable container 4 enclosing the polishing surface table 3 and provided with a window part 5 at a part facing the polishing surface table 3; a detachable cloth-like cover body 6 covering the window part 5 of the container 4 and closing the container 4; and pressure setting means 15-18 for increasing/reducing pressure in the container 4. A wafer 1 is disposed inside the window part 5 and between the polishing pad 2 and the cloth-like cover body 6. The pressure in the container 4 is made negative by the pressure setting means 15-18, and the polishing pad 2 is moved relative to the wafer 1 to polish the wafer 1. Chips, dust and particulates caused by polishing are thereby prevented from flowing out of the container 4, and since the wafer 1 is conveyed in and out of the window part 5 in the state of the downflow of air being generated in the container 4, the chips, dust and particulates in the container 4 are prevented from flowing out of the window part 5.