We demonstrate the fabrication of superhydrophobic, flexible and gas-permeable membranes by a simple one-step process consisting only of thermal evaporation of a fluid polydimethylsiloxane (PDMS) polymer, without the use of any other chemicals such as curing agents or solvents of PDMS. As a substrate for the PDMS coating, a stainless steel mesh approx. 100 μm thick was used, which is flexible and becomes superhydrophobic after PDMS coating, attaining a water contact angle above 160°. The flexible mesh remained gas-permeable upon superhydrophobic coating, since PDMS evenly coated each strand of the metal mesh, and the vacancies between wires remained unclogged upon coating. The mechanical and chemical stability of the superhydrophobic, flexible and gas-permeable membrane is demonstrated herein.