Filtering device for plastic material in the molten state, said filtering device comprising: - a hollow body (2.1) provided with a mouth and a cover (2.1) suited to be associated with said mouth to define a filtration chamber; - at least one inlet way (2.3) for the introduction of said plastic material in the molten state into said filtration chamber and at least one outlet way (2.4) for the discharge of the filtered plastic material in the molten state from said filtration chamber; - two filtering means (3.1) made up of a metal mesh and arranged side by side in said filtration chamber, said filtering means (3.1) defining a first compartment which communicates directly with said inlet way (2.3) and at least one second compartment which communicates with said outlet way (2.4); - a first holed support (3.2) and a second holed support (3.3), each first holed support and each second holed support (3.2, 3.3) being arranged in such a way that it adheres to one of the two sides of each filtering means (3.1), the holes of said first and second holed supports (3.2, 3.3) being larger than the meshes of the filtering means made up of a metal mesh (3.1); - a cleaning device arranged in said first compartment between said two filtering means (3.1); - an evacuation device (6, 7) suited to discharge said impurities collected by said cleaning device towards an evacuation outlet, said evacuation device (6, 7) being arranged centrally with respect to said cleaning device; characterized in that said cleaning device comprises one or more pairs of main hollow bodies (4.1', 4.1"), one or more pairs of adhering walls (4.2) which adhere to said second holed supports (3.3), moving means (4.4), and wherein each main hollow body (4.1', 4.1") is suited to be coupled with another main hollow body (4.1", 4.1') in a position diametrically opposite the latter and in such a way that they rotate integrally with each other and are free to translate along the common axis, and wherein each main hollow body (4.1', 4.1") is suited to support each of said adhering walls (4.2) so that it remains adherent to the surface of the corresponding second holed support (3.3) of a filtering means (3.1), and wherein each adhering wall (4.2) is provided with a slit or opening (4.2a) suited to place the surface of said adhering wall (4.2) that is in contact with the second holed support (3.3) in communication with the inside of the main hollow body (4.1', 4.1") to which said adhering wall (4.2) is joined, and wherein said main hollow bodies (4.1', 4.1") are provided with an internal connection duct (4.1d) suited to connect the seat (4.1s) of said adhering wall (4.2), the inside of each main hollow body (4.1', 4.1") and the inside of their central mutual coupling part (4.1a). - a hollow body (2.1) provided with a mouth and a cover (2.1) suited to be associated with said mouth to define a filtration chamber; - at least one inlet way (2.3) for the introduction of said plastic material in the molten state into said filtration chamber and at least one outlet way (2.4) for the discharge of the filtered plastic material in the molten state from said filtration chamber; - two filtering means (3.1) made up of a metal mesh and arranged side by side in said filtration chamber, said filtering means (3.1) defining a first compartment which communicates directly with said inlet way (2.3) and at least one second compartment which communicates with said outlet way (2.4); - a first holed support (3.2) and a second holed support (3.3), each first holed support and each second holed support (3.2, 3.3) being arranged in such a way that it adheres to one of the two sides of each filtering means (3.1), the holes of said first and second holed supports (3.2, 3.3) being larger than the meshes of the filtering means made up of a metal mesh (3.1); - a cleaning device arranged in said first compartment between said two filtering means (3.1); - an evacuation device (6, 7) suited to discharge said impurities collected by said cleaning device towards an evacuation outlet, said evacuation device (6, 7) being arranged centrally with respect to said cleaning device;