A variant of tape casting, involving phase inversion, was explored for the preparation of supported ceramic oxygen separation membranes in one step. A slurry of Zr0.84Y0.16O1.92 (YSZ) and La0.8Sr0.2MnO3-delta (LSM) powders in a N-methyl-2-pyrrolidone solution of polyethersulfone was tape cast, and immersed in water bath for solidification into a green tape. After sintering at 1320 degrees C a ceramic membrane was obtained with a total porosity of similar to 35%, consisting of a porous layer with thickness similar to 0.85 mm on a gastight top layer with thickness similar to 0.15 mm. An oxygen permeation flux of 1.90 x 10(-3) mol m(-2) s(-1) was observed at 900 degrees C by exposing the porous side of the membrane to air and the other side to helium. A supported membrane with the identical YSZ/LSM ratio, made by sequential two-step tape casting, with graphite as pore former, showed a flux of 3.31 x 10(-4) mol m(-2) s(-1). The difference in oxygen flux between the two membranes is attributed to the difference in resistance towards gas transport in the support layer It is concluded that the phase inversion tape casting is a simple and effective method for preparation of supported oxygen separation membranes. (C) 2013 Elsevier B.V. All rights reserved.