Our room-temperature UHV system contains an optimized OMICRON AFM/STM (see picture on the left). Sample preparation can be done in situ by molecular beam epitaxy (three e-beam evaporators). Furtheron the system is equipped with a sputter gun, a LEED/Auger system and an e-beam heating stage (up to 2600 K). A special feature of the system is an additional chamber, which allows the preparation of magnesium oxide films at elevated temperatures. It also contains a nitrogen plasma source in order to dope the films with atomic nitrogen.