A method for reprocessing used PET bottles having the steps of shredding the bottles to form plastic flakes, sorting the plastic flakes according to at least one criterion into at least two partial quantities, and performing an individual processing treatment including a decontamination treatment. The device permits performing the method whereby it is possible to separate the plastic flakes produced from the threaded part of a PET bottle, these flakes being more difficult to purify, from the lighter plastic flakes from the wall of the bottle, which have a thin wall and are easier to purify, and treating them further in separate reprocessing steps.