A detergent for removing deposits on a mold for use in molding a thermoplastic resin, comprising limonene and ethanol is disclosed. Provided, is a detergent for removing mold deposits, said detergent being capable of easily removing deposits (the so-called mold deposits) and anticorrosive agents, releasing agents, lubricants and the like from the surface of a mold in the process of molding the thermoplastic resin. Furthermore, the detergent is preferable from the viewpoint of the work environment, and said detergent can be apply to a wide range of thermoplastic resins.