The selectivity and permeability of membrane material determines the efficiency of the gas separation process. To prepare a stable high selective and high permeable membrane and, in addition, also cheap, is the dream of most scientists dealing with the membrane technology. We proposed to investigate the gas separation by a completely new type of membranes possessing both; high selectivity and high gas permeability. Our preliminary results are very promising. We are able to prepare a very cheap and very thin liquid film with high separation performance of test CO2/CH4 mixture. A next curiosity of the new type of membranes is the continuous regeneration of the liquid film during the separation process. Based on this fact, we named the liquid film "dynamic liquid membrane" (DLM). (C) 2016 Elsevier B.V. All rights reserved.