"In Europe, ever more private museums are now entering the field. This paper investigates the behavior of one of these private museums, using an institutional approach of cultural economics. The Beyeler museum in Basle, Switzerland, is a privately founded art museum with an extraordinary collection of art works. Though less than five years old, it is acknowledged to be the most successful museum in Switzerland in terms of number of visitors. However, the Beyeler museum is not completely private but receives public support. We analyze how this influences the museum’s behavior: (1) The directorate of the Beyeler museum stays away from the art market with its collection as public institutions do. (2) The museum embarks on a self-propelling process concerning special exhibitions, therewith losing some of its uniqueness. (3) Concerning visitors’ amenities, differences between private and publicnmuseums emerge but to a lesser extent than expected according to theory."