Filter for removing particles from a a gas stream comprises filter pockets having gas-permeable filter walls and containing a ribbed functional element

A filter means is disposed in an exhaust system of an internal combustion engine. It filters out particles from a gas stream (32) and comprises a housing and at least one arranged in the housing filter structure with filter bags (2). Will be limited by gas-permeable filter walls (24). At least one filter pocket (22) comprises a surface-mounted-on or functional element (34) bear against the mutually opposite filter walls at least region-wise. It is suggested that the functional element (34) has at least one rib (60) which abuts with a projecting edge (68) in a filter wall (24).