For the first time, a thin ionic liquid membrane that is resistant up to 55 bar trans-membrane pressure is presented. The ionic liquid is confined in a tubular ceramic-supported mesoporous containment layer of 1.5 mu m. Gas permeances and permselectivity values for CO(2), CH(4), ethylene, and ethane are discussed and related to the properties of the ionic liquids. (C) 2010 Elsevier B.V. All rights reserved.