PURPOSE: A filter comprising a porous metallic thin film is provided which efficiently removes dust even under a high temperature and a high pressure and is able to lengthen life. CONSTITUTION: The filter is formed by making many fine openings on a metallic thin film with keeping a regular space. The metallic thin film is shaped as a various structure such as a plate shape, a cylinder shape and a venturi shape according to it's uses. The fine opening has a size of 20-100 micrometers and is builded as a circular type, a horizontal slit type, a vertical slit type and a cross type according to physical properties of materials to be filtered.
