A thermoplastic resin composition for cleaning a molding processing machine, which has good cleaning performance and workability in cleaning an inner side of a molding processing machine of thermoplastic resin composition, such as an extruder and an injection molding and includes (A) an olefin-based resin, (B) a thermoplastic resin which is not compatible with the olefin-based resin of the component (A), (C) a thermoplastic resin for making the olefin-based resin of the component (A) and the thermoplastic resin of the component (B) compatible with each other, (D) an alkaline metal salt of a fatty acid, (E) a nonionic surfactant, and (F) a metal salt of an acidic phosphoric ester.