A filter device has a filter housing (1), at least one filter element (13) received in the filter housing (1) and an inner fluid space (71) limited by a filter medium (17) through which the fluid to be cleaned can flow. The filter medium separates the inner fluid space (71) from an exterior fluid space (11) located in the filter housing (1). The filter housing (1) has a fluid inlet (7) and a fluid outlet for cleaned fluid. A fluid guide device (9) is connected downstream to the fluid inlet (7) and can be optionally retrofitted to form a flow path between the fluid inlet (7) and the exterior fluid space (11) or between the fluid inlet (7) and the inner fluid space (71) disposed in the filter element (13).