The First Department (Первый отдел, Pervyj Otdel) was in charge of secrecy and political security of the workplace of every enterprise or institution of the Soviet Union that dealt with any kind of technical or scientific information (plants, R&D institutions, etc.) or had printing capabilities (e.g., publishing houses). The first departments reported to KGB and were not subordinated to the management of the enterprise/institution.

Among its functions was control of access to information considered state secret, of foreign travel, and of publications.

Also, the First Department kept account of the usage of copying devices (xerographers, printing presses, typewriters, etc.) to prevent unsanctioned copying, including samizdat.

They continue to exist in Russian Federation, with secrecy and security functions, excluding political control.