The article explores the organization, functioning, and internal practices of an 8th century Japanese scriptorium, the administrative records of which have been preserved as part of the Shōsōin documents (正倉院文書, Shōsōin monjo). The author views the activities of the scriptorium as not only a technical process, but as a social and religious practice reflecting power relations, economic mechanisms, and sacral meanings. The central focus of the analysis is the scriptorium’s project of transcribing the Mahāprajñāpāramitā Sūtra and two versions of the Avataṃsaka Sūtra in 754 — a project commonly referred to in historiography as the “Three Sūtras Transcription Project (三部経写経事業, sanbukyō shakyō jigyō). This undertaking was not only a religious initiative, but also a state-sponsored enterprise carried out within the framework of an emerging centralized bureaucratic system. Two key administrative documents from this project are examined as primary sources: a memorandum submitted by the Bureau for the Construction of Tōdaiji Temple (造東寺司解), petitioning for the allocation of materials for transcription, and a record from Hokkeji Temple (法華寺安置経勘受文) confirming the receipt, inspection, and enshrinement of the completed sutras. The translation and close analysis of these documents make it possible to reconstruct the overall operations of the scriptorium in the mid-8th century, revealing specific details of its workers’ daily labor, the mechanisms for resource distribution, the logic of administrative procedures, and the system of remuneration. The study suggests that the scriptorium functioned as a bureaucratic unit combining both secular and religious practices. Thus, the investigation of its activities and internal administrative processes sheds light on the broader sociopolitical and cultural functions of such institutions as centers for the reproduction of sacred texts, the cultivation of literary culture, and the articulation of statehood in Naraperiod Japan.