Abstract: A device for separating magnetic materials from non-magnetic materials in a sample using an applied magnetic field includes an inverted upstream funnel containing a plurality of longitudinally spaced, non-magnetisable flow-smoothing surfaces extending transversely across the width of the funnel, a coaxial filter chamber coupled to the output end of the upstream funnel having mounted therein an ordered wire array of magnetisable wires and a coaxial downstream funnel containing a plurality of longitudinally spaced, non-magnetisable flow-smoothing surfaces extending transversely across the width of the downstream funnel. The device may be used to separate magnetically labelled materials from samples such as biological samples.