Abstract: In order to create a rotating drum filter with a filter medium that is extremely fine-meshed and nonetheless has a long service life, whereby the filter medium need not be completely replaced given localized damage thereto, it is inventively proposed that the filter medium be formed of a composite element body with at least two metallic layers, namely with an extremely finely porous, outer metal layer or, respectively, stainless steel fabric that is firmly applied onto at least one metallic supporting grid layer or, respectively, onto a stainless steel fabric layer that is coarse-meshed compared thereto.