In an integral filter (F) for separating fluid components which filter can be enclosed in a surrounding housing (1,2) with fluid connections (A1 l to A3, 10) the permeable tube jacket of which filter consists of several tubular filter elements (K1, K2) with different filter qualities whose cross sections are stepped in such a manner that a smaller filter element is surrounded by a larger filter element, optionally with formation of an intermediary space (Z1), and in which the two tube ends are enclosed by closure and connection adapters (15, 20, 21, 22, 27, 31) and can be adapted to fluid chambers (13, 14) of the housing, sections of the total filter (F) can be selectively tested for integrity, supplied with and emptied of fluid and filling substances via an intermediary space (Z1) between two filter elements (K1, K2) which intermediary space can be separately controlled and loaded from the outside.