This paper attempts to discuss the methodology for media history by considering

the significance and limitations of multi-archival research. For several

decades, much interdisciplinary attention has been paid to multi-archival

research not only in the field of history but also political science, international

relations, and sociology. Multi-archival research became a popular and significant

method because it promoted the declassification of documents in archives

around the world after the end of the Cold War. This popular method has been

applied to the discipline of media history and it has provided a significant key

to opening a new dimension of its history in Japan at home and abroad.

　　For researchers who intend to conduct research using a multi-archival

approach, this paper aims to provide some information that was acquired

through my own archival research experience. It focuses on the following three

aspects. First, how my research interests spread beyond borders from Japan to

Korea, the U.S., China, the U.K., and so on, including how I recognized the usefulness

and significance of multi-archival research. Second, what we need to be

careful of when attempting to conduct multi-archival research and analyze

archival documents. Third, how we can utilize archives to gather documents

more efficiently. To answer these questions, this paper provides archival information

on the U.S., the ROK, the DPRK, Taiwan and the U.K.

　　The scope of this paper attempts to contribute to the argument,“ how can

we open a new dimension of media history by utilizing something new or old methods?”