NOVELTY - The filter (4) comprises a first filter unit having a body provided in a flow path of an exhaust gas, The first filter unit is connected to a power generation unit, is operated at a temperature of 300-500 degrees C, and converts chromium (VI) compounds into chromium (III) compounds. The filter is provided in an exhaust path of the power generating unit. The first filter body comprises a metal mesh, a metal foam or ceramic foam and a solid acid, and is coated or formed with Bronsted acid or Lewis acid. The second filter body is made of a metal mesh, a metal foam or ceramic foam.    USE - The filter is useful for separation of chromium (VI) compounds from exhaust gases of a power generating unit that is useful as a decentralized fuel cell system, a remote burner or an internal combustion engine (all claimed).    ADVANTAGE - The compact filter simply and economically removes chromium compounds from exhaust gases.    DETAILED DESCRIPTION - The filter (4) comprises a first filter unit having a body provided in a flow path of an exhaust gas, The first filter unit is connected to a power generation unit, is operated at a temperature of 300-500 degrees C, and converts chromium (VI) compounds into chromium (III) compounds. The filter is provided in an exhaust path of the power generating unit. The first filter body comprises a metal mesh, a metal foam or ceramic foam and a solid acid, and is coated or formed with Bronsted acid or Lewis acid. The second filter body is made of a metal mesh, a metal foam or ceramic foam. The filter further comprises a second filter unit (2), and a space (3) for receiving chromium oxide compounds located below the second filter unit. The second filter unit comprises a second filter body having a large specific surface, which is equipped with fixed bases. The space is formed so that gas stream flows in a direction of gravity or perpendicular to gravity and is deflected against the gravity in space. The power generating unit comprises an exhaust gas heat exchanger (7). The filter is arranged before the exhaust gas heat exchanger.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of a power generation unit.    Second filter unit (2)    Space (3)    Filter (4)    Exhaust gas heat exchanger (7)    Fuel supply. (12)