The invention relates to a spin-on filter for filtering a flowing substance, especially to a filter for hydraulic liquid or lubricating oil in combustion motors. The filter comprises a casing, which is openable at one end, a substantially cylindrical replaceable filter means fitted inside the casing, the flow to be filtered having been arranged to pass through the filter means mantle, and a collar for connecting the filter with a device assembly, which includes inlet and outlet ducts for flow to...