Since 2005, the new building of Matica slovenská has been the seat of the Slovak National Library which is a modern scientific, cultural, and educational institution. The main mission of the library is to provide library and information services to the public. In a broader context, its mission encompasses a wide range of activities aimed at “collecting, preserving and publishing library-, archive-, and museum collections of literature written by Slovak authors, published/produced on the territory of Slovakia, and written in the Slovak language or relating in any way to Slovakia.” 
The composition of the building’s masses is reflected in the layout and the mutual visual conjunction of the interior and exterior, which is enhanced by the existence of two internal atriums. The interior design, preserved to this day, is an excellent representation of the “total interiors” idea promoting a comprehensive approach to design from the whole to the architectural and artistic detail. Daniela Dobešová visited the premises and described them as follows: “The comprehensive form of the interior is characterised by the uniform design with clearly defined functions of the spaces. The main spaces of the building´s first floor include a lobby, a lecture hall, and a café/reading room for library visitors. The first floor also serves as a space for exhibitions. On the second floor, there are the premises of the interlibrary information service, children’s corner, and the main university study room named “the Golden Thread”. Atypical furnishings, designed specifically for this space, bring variety and a unique atmosphere. The authors designed everything from sofas, cabinet sets, and shelves to details such as ashtrays and dustbins. They placed great emphasis on the quality of production of the design elements which were made of high-quality materials and with craft precision. The interiors of the Slovak National Library are characterised by a unified shaping of furnishings which are in harmony with the building interior elements. Round shapes can be found on columns, railings, stairs, seating furniture, tables, and lamps. The spaces are dominated by white, orange, green and blue colours, which can be seen in varying proportions especially on the building interior components – panelling and railings. The modern character of the whole interior is emphasised by the stainless steel used on the columns and some pieces of furniture.” 
“The current state of the interiors of the Slovak National Library corresponds to a large extent to the original design. The original form of the individual elements was preserved to the most possible extent during the renovation. Only partial changes have been made, such as the change of the graphic design of the information desk signage on the second floor. In this area, the lights and the upholstery on the chairs have also been replaced. The university study room has undergone some partial changes; however, the symmetrical arrangement of the space has been maintained. The original chairs have been replaced with new ones; however, their design is not fully consistent with the visual signs of the original furniture. A children’s playroom on the second floor, which has been added, does not also fully correspond to the overall interior concept. The interior of the lobby on the first floor has also been partially changed, where lockers have been added to serve as storage space for visitors.”  Due to technological innovations, the ceilings have undergone some structural adjustments too.
Architecture and fine arts blend nicely in both the interior and exterior spaces of the building. These are complemented by a number of masterpieces by prominent Slovak artists, enhancing the visual and perceptual experience of visitors. The lobby on the ground floor is decorated with a glass sculpture by Václav Cígler; the author of the busts of significant Slovak figures is Fraňo Štefunko. The wall in front of the entrance to “the Golden Thread” study hall is decorated with a large oil painting by Milan Laluha. The interior of the study hall presents a white gypsum relief by Elena Bellušová. 
Thanks to the preservation of period artefacts, the interior of the building still keeps its original atmosphere which Daniela Dobešová summarised as follows: “My impression of the premises of the Slovak National Library is that it is a very noble space which corresponds to the purpose for which it is intended. The interiors represent high quality interior design of the second half of the 20th century. For me personally, the most positive aspect is the overall atmosphere of the individual spaces and a unique experience that a visit to this type of interior can bring even today. The most visually interesting elements include the seating in the lobby and the lights on the second floor which both bear the hallmarks of Vojtech Vilhan’s work.”