Abstract: A filter material and method for its preparation for separation of hydrophilic substances from environment of various hydrophobic liquids or gases. Such hydrophobic substances can be different chemical and oil products, substances of biological origin (fats, essential oils). Hydrophilic substance can be water, lower alcohols (methanol, ethanol), polybasic alcohols, substances dissociating in aqueous solution (salts, acids or bases). Filter material is in the form of oxygen containing polymer, which microscopic and macroscopic structure forms during polymerization process. More precisely the filter material consists of polyacetal for example polyvinylacetal. Polymeric structure of filter material forms during synthesizing reaction of the polyacetal by the action of the assisting substances taken into reaction medium.