A processed article is provided with a plurality of IDs having the same information for machine reading but difference to be confirmed visually. The information such as the production lot number which is read from the plurality of IDs by the reading device is the same, but these plurality of IDs are different in external appearance, for example in size or color. By corresponding such difference of the plurality of IDs in the external appearance to the positional information in the processing apparatus for the article, new information can be added to the ID without introducing a new ID printer or a reading device. A prompt measure to a trouble in production is made possible based on the information such as the position of the article. Also the defective processed article can be easily selected, thereby improving the production yield and achieving a cost reduction.