a filtering device for highly viscous media comprises at least one screen plug which is movably arranged in a screen plug bore of a housing and which has at least one screen cavity , a filter element lying in said screen cavity . the screen cavity narrows to a funnel section in a rear region when viewed in the flow direction , said funnel section opening into at least one screen plug outlet channel that opens upstream of the housing outlet channel in the production position . according to the invention , the screen plug outlet channel comprises an inlet zone , at least one deflecting point , and an outlet zone . the intake zone extends from an edge region of the funnel section , and the outlet zone is designed as a groove that extends on the outer face of the screen plug and / or on the inner face of the screen plug bore .