The Museum has three galleries for its permanent collection, arranged on the three floors of its 17th-century building. The Top Gallery is devoted to mathematical instruments (astrolabes and spheres, measurement and calculation, Medieval and Renaissance, East and West). The Entrance Gallery has the reception and shop, introductory objects, a small temporary display space and four “corner collections”. The main Basement Gallery displays chemical, physical and medical items, along with Einstein’s blackboard. The Special Exhibition Gallery is also at basement level. There are usually two temporary exhibitions there each year.
To prepare for your visit you might like to consult the Museum Guide and Plan [pdf]  which includes floor plans of the building.