PURPOSE: To collect fine particles of submicron and to burn them by oxidation to make them harmless in a fine particle-contg. fluid, such as exhaust gas.

CONSTITUTION: In a nozzle pipe 2 equipped with an intake 3, a nozzle part 5 through which fine particle-contg. gas is passed to be turned into a high-speed swirling flow, is installed. In a cylindrical case 1 where the high-speed swirling flow is transferred, a bar electrode 12 equipped with a needle electrode part 14 and a cylindrical electrode 15 are installed, and a high-voltage DC power source 25 is connected to form the high-voltage static electric field. Fine particles passing through the static field are charged and agglomerated to be turned into larger particles, making centrifugal separation easy. The fine particles centrifugally separated are burned by oxidation in a burning part 18 of the cylindrical electrode 15 to be made harmless. The burning part 18 is formed, packed with catalytic fiber carried on glass fiber and metal fiber. The fluid after fine particle separation is restored its pressure in a diffuser part 10 of a diffuser pipe 7 and is discharged from a discharge port 8.