The present disclosure provides an automatic processing apparatus including a main body, a receiving portion, a working assembly, a workpiece magazine, a setting mechanism, a passivation bucket assembly, and a rotation driving assembly. The receiving portion is adapted for receiving a plurality of workpieces. The setting mechanism takes the workpieces to the receiving portion from the workpiece magazine. The working assembly is adapted for bringing the workpieces to the passivation bucket assembly for processing. The passivation bucket assembly includes a turning table and a plurality of passivation buckets moving when the turning table rotates. The rotation driving assembly drives one of the passivation buckets to rotate. Thereby, automatic processing can be achieved by the apparatus of the present invention, and the efficiency of processing is improved too.