Device for the continuous filteration of molten plastic material comprising: - a body, - a cavity inside the body that creates a chamber; - a hollow perforated cylinder that rotates around its main axis inside said chamber; - an inlet opening on the body for putting the plastic material to be filtered into the chamber, and - an outlet opening where the filtered plastic material comes out from the body, - a connection opening that connects the outside of the body with said chamber on the inside, - a filtration mesh belt that enters the chamber through the said connection opening and exits through said connection opening after having carried out the filtration; where - a section of inlet-mesh that enters the chamber from outside of the body through an inlet path into the connection opening, and continues on, - a section of adjoining-mesh that remains attached to the outer surface of said hollow perforated cylinder, and that continues on, - a section of outlet-mesh that exits the body from the chamber through an outlet path in the connection opening, - where said inlet-mesh, said adjoining-mesh and said outlet-mesh are a continuous mesh; characterised by the fact that comprising: - a mobile cone that creates, together with the body, said inlet path and the said outlet path, where said cone can move between a first closing position and a second opening position on the connection opening that connects the outside of the body with said chamber and that, in the first closed position, closes the inlet path with a section of inlet-mesh interposed and closes the outlet path with a section of outlet-mesh interposed, and in the second opening position opens the inlet path and opens the outlet path, where said filtering mesh strip can slide in said openings (10, 11); - where said inlet path is a first channel between the outside of the body and the inside of the chamber, with a width corresponding to the width of the mesh strip and enclosed between the body itself and a first side wall of the cone; - and where said outlet path is a second channel between the outside of the body and the inside of the chamber, with a width corresponding to the width of the mesh strip and enclosed between the body itself and a second side wall of the cone; - where said mobile cone has a base wall between said first and said second side wall, facing the inside of the chamber, and facing the perforated hollow cylinder. - a body, - a cavity inside the body that creates a chamber; - a hollow perforated cylinder that rotates around its main axis inside said chamber; - an inlet opening on the body for putting the plastic material to be filtered into the chamber, and - an outlet opening where the filtered plastic material comes out from the body, - a connection opening that connects the outside of the body with said chamber on the inside, - a filtration mesh belt that enters the chamber through the said connection opening and exits through said connection opening after having carried out the filtration; where - a section of inlet-mesh that enters the chamber from outside of the body through an inlet path into the connection opening, and continues on, - a section of adjoining-mesh that remains attached to the outer surface of said hollow perforated cylinder, and that continues on, - a section of outlet-mesh that exits the body from the chamber through an outlet path in the connection opening, - where said inlet-mesh, said adjoining-mesh and said outlet-mesh are a continuous mesh; - a mobile cone that creates, together with the body, said inlet path and the said outlet path, where said cone can move between a first closing position and a second opening position on the connection opening that connects the outside of the body with said chamber and that, in the first closed position, closes the inlet path with a section of inlet-mesh interposed and closes the outlet path with a section of outlet-mesh interposed, and in the second opening position opens the inlet path and opens the outlet path, where said filtering mesh strip can slide in said openings (10, 11); - where said inlet path is a first channel between the outside of the body and the inside of the chamber, with a width corresponding to the width of the mesh strip and enclosed between the body itself and a first side wall of the cone; - and where said outlet path is a second channel between the outside of the body and the inside of the chamber, with a width corresponding to the width of the mesh strip and enclosed between the body itself and a second side wall of the cone; - where said mobile cone has a base wall between said first and said second side wall, facing the inside of the chamber, and facing the perforated hollow cylinder.