The invention relates to a portion capsule for producing a beverage, having a capsule body with a capsule base and a filling side. A cavity for receiving a pulverulent or liquid beverage substrate is formed between the capsule base and the filling side, and a filter element is arranged between the beverage substrate and the capsule base. The filter element comprises an open-pore felt and/or nonwoven fabric, and the felt and/or nonwoven fabric has a first average pore size in a first region facing the beverage substrate and a second average pore size in a second region facing the capsule base, said first pore size being smaller than the second pore size.