Abstract: A resolving issue of manufacturing an underlay mat enabling the easy installation, which meets high requirements regarding utility properties and durability despite low costs of materials and production, as well as good tolerance by the natural environment. This task is fulfilled by the underlay mat for floor coverings, which contains: the foamed polystyrene layer, the PET (polyethylene terephthalate) film on the top side of the polystyrene layer, the layer of adhesive applied on the PET film and the removable protective layer applied on the layer of adhesive.