A spin-on filter for a filter device with a housing pot in which a filter element is arranged, a connecting body arranged at the housing port end face having a central opening and a fluid opening radially outwardly offset from central opening. A filter-side coupling part of a coupling device detachably couples the spin-on filter to a filter head. The coupling part can be detachably coupled to a connector of a head-side coupling part of the filter head by way of a plug-in and/or rotational movement with respect to a coupling axis. A inner seal is provided having a sealing surface which extends around the periphery of a centric fluid channel and is axially offset in relation to the filter-side coupling part toward the filter element. The circumferential sealing surface of the filter head-side fluid connector sealingly contacts to separate the dirty and clean sides.