The communiqué deals with the problems enceuntered in conservation of plaster in the ground floor section o f the Town Hall in Poznań. As a result of the action o f external factors and, also, o f the lack o f vertical and horizontal insulation in the ground floor section o f the edifice, its plaster there was most decayed and the dirtied. In view o f the necessary partial drying o f the wall, the method of a certain infiltration o f humidity in wall bearings has been applied as the most appropriate one. A project has been worked out for application of the so-called spacing plaster spread from the bottom part of the Town Hall up to the curstable. The insulation space thus created was meant to cut the layer of plaster from spotscaused by humidity in the wall and eliminate the so-called bridges conveying moisture. The author describes in greater detail the process of preparation of „distance plaster” which consists, roughly speaking, in the respective layers of plasters (of which one mixed with bristle) being applied on a suspended lath spread on an adequately designed supporting construction. As a result o f this proceeding an air space of 2—3 cm was created between the wall of the Town Hall and its plaster. The method of application o f spacing plaster has made it possible to attain both the intended conservation, technical and aesthetic objectives. It was on this route, too, that — without any radical change in humidity conditions persisting in its walls for centuries past — the ground floor part of Poznan Town Hall has been protected from the spots and efflorescence marring its beauty.