Abstract: The invention relates to a filter device for the physical elimination of microbes, suspended matter and solids from water, which in a housing has a filter insert made of 200 to 10000 hollow-fiber membranes with a defined pore width between 0.001 and 1.0 &mgr;m and which can be mounted on a water tap with its top side. A disadvantage of previously known filter devices is that deposits will adhere to the fibers. In order to remedy this drawback, the bottom side of the device of the invention features separate outlets for filtered and unfiltered water and at least in the outlet for the unfiltered water a valve is fitted with which this outlet can be closed.