A sensing structure for an accelerometer , comprising: a support and a proof mass mounted to the support by flexible legs for in-plane movement in response to an applied acceleration along a sensing direction ; the proof mass comprising a plurality of moveable electrode fingers extending substantially perpendicular to the sensing direction and spaced apart in the sensing direction ; at least four fixed capacitor electrodes , each comprising a set of fixed capacitor electrode fingers extending substantially perpendicular to the sensing direction and spaced apart in the sensing direction ; each set of fixed capacitor electrode fingers being arranged to interdigitate with the movable electrode fingers ; the proof mass being mounted to the support by a proof mass anchor 104) located on a centre line of the proof mass , the centre line being perpendicular to the sensing direction ; wherein the proof mass takes the form of an outer frame surrounding the at least four fixed capacitor electrodes , the flexible legs extending laterally inwardly from the proof mass to the proof mass anchor ; wherein the at least four fixed capacitor electrodes comprises two inner fixed capacitor electrodes , one on each side of the centre line of the proof mass , and two outer fixed capacitor electrodes , one on each side of the centre line of the proof mass ; characterised in that each of the two inner fixed capacitor electrodes comprises an anchored part anchored to the substrate and a cantilevered arm extending from the anchored part away from the centre line and having fixed capacitor electrode fingers mounted thereto; and each of the two outer fixed capacitor electrodes comprises an anchored part anchored to the substrate at a location that overlaps in the sensing direction with the cantilevered arm of an inner fixed capacitor electrode and a cantilevered arm extending from the anchored part away from the centre line and having fixed capacitor electrode fingers mounted thereto. a support and a proof mass mounted to the support by flexible legs for in-plane movement in response to an applied acceleration along a sensing direction ; the proof mass comprising a plurality of moveable electrode fingers extending substantially perpendicular to the sensing direction and spaced apart in the sensing direction ; at least four fixed capacitor electrodes , each comprising a set of fixed capacitor electrode fingers extending substantially perpendicular to the sensing direction and spaced apart in the sensing direction ; each set of fixed capacitor electrode fingers being arranged to interdigitate with the movable electrode fingers ; the proof mass being mounted to the support by a proof mass anchor 104) located on a centre line of the proof mass , the centre line being perpendicular to the sensing direction ; wherein the proof mass takes the form of an outer frame surrounding the at least four fixed capacitor electrodes , the flexible legs extending laterally inwardly from the proof mass to the proof mass anchor ; wherein the at least four fixed capacitor electrodes comprises two inner fixed capacitor electrodes , one on each side of the centre line of the proof mass , and two outer fixed capacitor electrodes , one on each side of the centre line of the proof mass ; characterised in that each of the two inner fixed capacitor electrodes comprises an anchored part anchored to the substrate and a cantilevered arm extending from the anchored part away from the centre line and having fixed capacitor electrode fingers mounted thereto; and each of the two outer fixed capacitor electrodes comprises an anchored part anchored to the substrate at a location that overlaps in the sensing direction with the cantilevered arm of an inner fixed capacitor electrode and a cantilevered arm extending from the anchored part away from the centre line and having fixed capacitor electrode fingers mounted thereto. <EOS>