A membrane support, usable for example in a membrane filtration device, comprises a support surface provided on an upstream side of the membrane support and adapted to support a flat filtration membrane thereon, and a drainage structure arranged below the support surface to collect a fluid that has passed the filtration membrane supported on the support surface and guide the fluid away to a downstream side, wherein the support surface has a plurality of recesses distributed over the support surface and formed to absorb expansions of the filtration membrane. The membrane support avoids fold formation of a membrane due to membrane expansion after hydration.