ENThe author has analysed structure and principles of organization of Chancery of the Grand Duchy of Lithuania in the 40th Years 15 - First Half of 16 Centuries. Has defined functional duties of Employees of Chancery: the chancellor, highest clerk (highest secretary, secret secretary), senior clerk, clerk (pisar), scribe (d’yak). The author names names of the employees, which in different time executed various posts in Chancery of the GDL.