This diploma thesis focuses on a project of new building of Planetarium in Prostějov in Olomouc district. The project is in accordance eith official assignment and with contemporary Czech standards and legislation. Building is placed to biggest park of Prostějov, next to the centre of city on an empty plot owned by city. Object should serve to the people as a cultural centre. The building plan is irregullarly-sharped with maximum dimensions 47,6 x 26,6 m and has three floors. On the first floor is galery, literature store and cafe and on the second floor is projection room and observatory. Structural systém is skelet and walls from reiforced concrete. Foundations of the building are made of concrete strip foundation and reiforced concrete square footings and strip foundations. Ceilings are made of reiforced concrete panels. There are roofs made by steel cupolas. Unsound walls are made of porous fittings. All external walls and cupolas are insulated with mineral wool. Doors and windows have aluminium frame and triple glazing, inner doors are wooden. As result there’s structurally, operationally and aesthetically functional complex, that will be benefit for the city and its citizens, especially for their cultural life.