Filter means, together with the filter element

A filter device for filtering fluid, especially in the form of an aqueous urea solution, with a filter housing (1) and disposed therein a filter element (11) and a compensation element to compensate for pressure or volume variations of the fluid, characterized in that the compensation element at least one elastically flexible hollow body (31; 41) is inserted, which has in one direction a larger spatial extent than in another, transverse to the direction, in a holding part (17; 43) is held and, with its wall a separation between the and a compressible fluid filling medium, such as a working gas makes.