EN
Various types of rotting wood microhabitats are presented, basing on many years of the authors studies carried out mainly in the nature reserve „Las Bielański" in Warsaw. The conditions of the formation of rotting wood microhabitats are given and the fauna of Coleoptera inhabiting particular types of rotten wood is described. For more interesting species details of their biology and morphology are given. Also some remarks on the protection of insects related to tree hollows are included.