Abstract: A filter device including a first filter having a first packing accommodated in a first sleeve thereof, and a second filter having a second packing accommodated in a second sleeve thereof, each one of the first and second packings cooperating with two retainer plates and a core bar to constitute a corresponding one of first and second filter elements, the two retainer plates being disposed on axially opposite ends of the corresponding one of the first and second packings, the core bar axially extending to pass through a center of the corresponding one of the first and second packings such that the two retainer plates engage the core bar at respective opposite ends of the core bar, the core bar being provided with a pull tab at one of the opposite ends of the core bar, so that the first and second packings are introduced and removed into and from the first and second sleeves, respectively.