A capacitive micromechanical accelerometer comprising - a substrate which defines a substrate plane which extends in a transversal direction and a longitudinal direction, the transversal direction being perpendicular to the longitudinal direction, - a first sensor formed in the substrate for measuring acceleration along a vertical axis perpendicular to the substrate plane, and - an accelerometer package with at least one inner package plane which is adjacent and parallel to the substrate plane, wherein - the first sensor comprises a rotor which is mobile in relation to the substrate, a rotor suspender and one or more stators which are immobile in relation to the substrate, - the rotor comprises one or more rotor electrodes and the one or more stators comprises one or more stator electrodes, the electrodes being configured for differential capacitive measurements, - the rotor suspender comprises one or more transversal torsion springs (191, 193, 591, 593, 691, 693) attached to the rotor, wherein the torsion springs are aligned on a transversal rotor rotation axis, characterized in that - the rotor is a seesaw frame comprising at least a transversal rotor bar (13, 53, 63), a first longitudinal rotor bar (14, 54, 64) attached to the transversal rotor bar and a second longitudinal rotor bar (15, 55, 65) attached to the transversal rotor bar, and - at least one longitudinal rotor bar (14, 15, 54, 55, 64, 65) comprises one or more first deflection electrodes, and a second deflection electrode (201, 202) is fixed to the inner package plane above and/or below each of the one or more first deflection electrodes, so that each of the one or more first deflection electrodes overlaps in an overlap area (31, 32, 41, 42) with the projection of the corresponding second deflection electrode (201, 202) in the substrate plane. - a substrate which defines a substrate plane which extends in a transversal direction and a longitudinal direction, the transversal direction being perpendicular to the longitudinal direction, - a first sensor formed in the substrate for measuring acceleration along a vertical axis perpendicular to the substrate plane, and - an accelerometer package with at least one inner package plane which is adjacent and parallel to the substrate plane, wherein - the first sensor comprises a rotor which is mobile in relation to the substrate, a rotor suspender and one or more stators which are immobile in relation to the substrate, - the rotor comprises one or more rotor electrodes and the one or more stators comprises one or more stator electrodes, the electrodes being configured for differential capacitive measurements, - the rotor suspender comprises one or more transversal torsion springs (191, 193, 591, 593, 691, 693) attached to the rotor, wherein the torsion springs are aligned on a transversal rotor rotation axis, characterized in that - the rotor is a seesaw frame comprising at least a transversal rotor bar (13, 53, 63), a first longitudinal rotor bar (14, 54, 64) attached to the transversal rotor bar and a second longitudinal rotor bar (15, 55, 65) attached to the transversal rotor bar, and - at least one longitudinal rotor bar (14, 15, 54, 55, 64, 65) comprises one or more first deflection electrodes, and a second deflection electrode (201, 202) is fixed to the inner package plane above and/or below each of the one or more first deflection electrodes, so that each of the one or more first deflection electrodes overlaps in an overlap area (31, 32, 41, 42) with the projection of the corresponding second deflection electrode (201, 202) in the substrate plane.