In the Prosecution Service Act, it is prescribed that the attending officer of the public attorney has the role of the document officer and the helping agency for the public attorney. As the helping officer, he participate in the interrogation of the public attorney and put questions to the suspect or witness and other persons.As for the questioning of the attending officer, it was judged by the Court in this case that it is allowed, but has limitations. First, the public attorney should in person put questions about the important matters and after it, the attending officer can put questions about details or ambiguous answers. Second, during the question of the attending officer, the public attorney should be present the interrogating place with the attending officer and preside the process. There are some people who insist that the attending officer’s questioning should be prohibited and the public attorney should put all questions in person. But this opinion does not accord with the current law. On enacting the Prosecution service Act, the legislature made the choice with the provision §46 ① 1. that allows the attending officer to do the works relating to the investigation which the public attorney orders. It is thought that this choice would be made because of the insufficient numbers of the public attorney and the necessity of the sharing the burden of works.Considering the overweighting burden of works for the public attorney, the Court’s interpretation could be said to be right to the present. But in practice, if we can say the public attorney’s interrogation, the role of the attending officer should be limited within the supplement of the factual work.