A description is given of the prototype polarized neutron reflectometer installed at the intense pulsed neutron source. This instrument is designed for determining the magnetic depth profiles near the surfaces of ferromagnets and superconductors, by measuring the spin‐dependent reflectivities of a well‐collimated (0.01°) beam of cold neutrons from surfaces of a few cm2. Magnetic profiles can be determined with the spatial resolution of 40 A˚, over thicknesses up to 5000 A˚. Variations of the magnetic flux of the order of 10−5G cm2can be detected.