Abstract: The invention relates to a cell culture insert (1) comprising a beaker-shaped insert wall (11), a base (9) consisting of a membrane filter, projecting support arms (3, 4) that are distributed around the periphery of the top and lateral spacers (7, 8) for a vertical and horizontal orientation in a well (2) containing a liquid culture medium (N) in a cell culture plate. According to the invention, the spacers (7, 8) are distributed around the periphery of the cell culture insert (1) and have different radial lengths in such a way that a large feed opening (5) and several smaller openings (5A) are formed.