Abstract: In order to provide a spacer for filter modules which may be used not only for plate and frame filter modules, but also for spiral wound-type filter modules and which allows high packing densities while providing optimized cleanability, a spacer for filter modules is proposed to be disposed between two layers of a filter medium, said spacer comprising an essentially flat structured sheet material having upper and lower projections on the upper and lower surfaces thereof, respectively, said upper and lower projections defining an upper and lower bearing face for the layers of filter medium, wherein said projections rise from said upper and lower surfaces with wall portions and terminate in top portions, said upper and lower projections being spaced from each other in a direction parallel to the surface of the sheet material.