In terms of formal arrangements, content, and space distribution, the museum is divided into several parts: the iconotheque, which holds the collection of visual theatre materials: scene photographs, scene set and costume designs, theatre programs and posters, artistic materials, etc.; the theatre archive, which holds all the written heritage: personal legacies and manuscripts of theatre creators, as well as other forms of written materials; the audio collection and video archives, which holds audio and video recordings; the specialized theatre library, which holds the entire collection of Slovenian theatre works, and the department for educational theatre programs, which is aimed at children, youth, adults, families and vulnerable groups.

Some of the most cherished artifacts in the museum are certain manuscripts and letters of the grandest creators of Slovenian theatre, such as Ivan Cankar, some statues and portraits of Slovenian theatre elite, as well as creations by prominent artists, such as scene designs by Avgust Černigoj, the founder of constructivism, one of the best-known representatives of the historical avant-garde in Slovenian fine arts.