Through the Delian League, Athens put great value on their activities in the sanctuaries as part of the process of promoting their "imperialism". The Panathenaea festival is a good example to show how the alliance was placed under Athenian control through offerings to sanctuaries during this period. Considering this point, the sanctuaries were excellent places for late fifth century Athens to visualize their authority, as the tyrants did in the sixth century. And Delos was also one of the most important sanctuaries for Athens in the early stages of the Delian League's history. It has been suggested that its "Ionian character" was a crucial aspect in establishing it as a place for the bank of the league, but there is more to this story. In this paper, the author deals with the relationship between Athens and the Delian sanctuary in the late fifth century, especially focusing on the Athenian administrators of the sanctuaries who were called the Amphiktyones. These administrators came into existence in the history of Delos by 434 B.C. at the latest, that is, after the transfer of the bank of the Delian league from Delos to Athens. Why did Athens maintain this sanctuary during the Peloponnesian war? This question is the starting point of this paper. To address this problem, the author will summarize the role of the Amphiktyones in the Delian sanctuary by observing their accounting records ID 89, 91, 92, 93, and 94. From these records it could be said that the Amphiktyones took charge of the asset management that related to the operation of the Delia festival even in the middle of the war. A second question arises, that is, whether this was a special case for contemporary Athens or not. In the second place, to compare with the other sanctuaries which the Athenians managed at the same period in mainland Greece, the author examines the evidence from the acropolis in Athens. Because Thucydides' account of the financial situation of Athens (2.13), and a famous inscription IG I^3 52, the so-called "Kallias decree" is important evidence to consider in the relationship between Athens and the sanctuaries. The author also considers the chronological problem of the establishment of "tamiai of the other god" in the acropolis in Athens as the background of the appearance of these two administrators, the Amphiktyones and the "tamiai of the other god" respectively. To conclude, the reason why the Athenians persisted in the control of the Delian sanctuary was not only because of its Ionian character, but also because of Athenian respect for the traditional religion which had been brought down by the social instability, such as plague and war. Moreover the appearance of the Amphiktyones was not a special case, but one of the many reforms in 430's Athens.