Most archae bacteria posses cell walls. But their cell wall structure and chemical composition is very different from that of eubacterial peptidoglycan cell wall.Their cell wall is made up of polysaccharides and proteins (glycoproteins).
A few genera, such as methano bacterium have walls composed of pseudomurein, a polymer whose structure superficially resembles eubacterial peptidoglycan but differs markedly in chemical compositions. The cell membrane contain branched lipids which help them to tolerate extreme temperature and pH. Read more
Polar lipids are present in archae bacterial membranes: phospholipids, sulfolipilds and glycolipids. 7 to 30% of the membrane lipids are non polar lipids.