Abstract: A sensor for a nuclear magnetic resonance device includes a magnetic field generation apparatus with a planar magnet arrangement for generating a static magnetic field in a useful volume. The planar magnet arrangement has a plurality of magnetic poles on a front side facing the useful volume, which are arranged adjacent to each other along an extension direction of the planar magnet arrangement with alternating orientation, and a measuring apparatus for measuring a signal based on nuclear magnetic resonance of a material sample arranged in the useful volume. The measuring apparatus includes an electrical coil having a winding for generating an alternating magnetic field in the useful volume, the winding arranged between two directly adjacent magnetic poles of the planar magnet arrangement such that the alternating magnetic field of the electrical coil is superposed with the static magnetic field of the planar magnet arrangement orthogonally in the entire useful volume.