The article deals with modern problems of studying a museum оbject as a source of knowledge of the past, and a museum exhibit as a mediator of the formation of museum culture among visitors. Particular attention is paid to the study of the properties and values of the museum object and exhibit in the scientific-fund and research activities of the museum. The complexity of the indicated problems provokes the uncertainty of terminological boundaries, which neutralizes the dynamics of the process of restructuring the fundamental cultural meanings that exist in the modern museum space. Thе problem can be solved by museum heuristics as a separate area of museum research.