A filter material for a fluid, particularly a hydraulic fluid, has a multi-layer filter medium (10) through which a fluid can flow and having a filter layer (20) and a drainage layer (32) forming a three-dimensional structure designed to enlarge the flow channels formed for the fluid to flow through. The drainage layer cooperates with an adjacent drainage layer and/or has individual line elements (33) that form a mesh or grid structure. Those line elements are arc-shaped or curved at least to some extent.