SUMMARY
In the work there are presented the results of investigation of digital libraries functionality and their practical use in the creation and exploitation of the Scientific Electronic Library of NAPS of Ukraine. There are presented the main sections of instructional features of the electronic library functional capabilities such as: user registration, management of deposits, browsing the library repository, simple and advanced searches in storage by years, academic institutions, authors and subjects covered as well as the rights and opportunities for the administrator, editor and library repository users are highlighted. In the article there are practical recommendations on rational choosing of software and implementation of the main sections of functionality capabilities of the EL systems.