METHOD FOR PRODUCING THERMOPLASTIC RESIN CONTAINING REDUCED AMOUNT OF FOREIGN MATTER, METHOD FOR PRODUCING THERMOPLASTIC RESIN COMPOSITION CONTAINING REDUCED AMOUNT OF FOREIGN MATTER, AND METHOD FOR PRODUCING THERMOPLASTIC RESIN MOLDED ARTICLE CONTAINING REDUCED AMOUNT OF FOREIGN MATTER

PROBLEM TO BE SOLVED: To provide a method for producing a thermoplastic resin having a reduced content of foreign matter such as gel, in which the time until a filter unit used for filtration is clogged is long while effectively reducing the amount of the foreign matter contained therein by filtration, and which is suitable for the continuous production of the resin.SOLUTION: The method for producing the thermoplastic resin containing the reduced amount of the foreign matter includes a filtration step of reducing the amount of the foreign matter contained in the thermoplastic resin. Solution filtration for filtering a solution containing the thermoplastic resin is adopted in the filtration step, and the solution filtration is carried out by passing the solution through a first filter unit having a filtration accuracy of ≥15 μm and ≤100 μm, and further passing the resultant solution through a second filter unit having a filtration accuracy of ≤5 μm.