Abstract: The invention relates to a flush-back filter, in particular for the filtration of oil, having filter elements (filter cartridges) arranged in a circle in the filter housing and a flushing member rotatable around the filter axis for the back-flushing of filter elements with the filtrate. According to the invention said filter elements are arranged on at least two concentric circles within the interior of said filter housing whereby said filter elements lying on one circle are located in the gaps between said filter elements lying on the other circle. For back-flushing of said filter elements horizontal on the concentric circle, there is a common flushing member below and with a small radial dimension, which is driven by a rotary drive. The back-flush filter has at least fourteen to twenty filter elements. Furthermore, a safety filter is arranged on the interior of the filter housing, which encircles said filter elements.