Under the Rules of Procedure, Ancient Nessebar Museum is a municipal scientific, cultural and educational institution that participates in the implementation of the state policy on protection of cultural monuments in the National archaeological and architectural reserve "Ancient Nessebar" and on the territory of the Municipality of Nessebar.

The museum is a legal entity with its own budget, a secondary authorizing body, applying the system of delegated budgets.

Its primary function is collection, documentation, preservation, study and popularization of cultural monuments.