Extruded polystyrene foam insulation board produced using environmentally friendly, CFC- and HCFC-free gases, in accordance with European regulation EC 2037/2000, with thermoplastic properties and a closed-cell structure, which gives the product excellent thermal and mechanical properties. The panel has excellent insulating properties and thanks to its low thermal conductivity and therefore high thermal resistance, it provides optimal thermal insulation, allowing for high energy savings.