This disclosure describes a capacitive micromechanical accelerometer with at least a first sensor which comprises a rotor which is a two-sided seesaw frame. The rotor comprises one or more first damping plates on the first side of its rotation axis and one or more first damping plates on the second side of its rotation axis. One or more second damping plates are fixed to the inner package plane above or below at least some of the one or more first damping plates, so that at least one first damping plate overlaps with the projection of a second damping plate on each side of the axis. The frame-shaped rotor may surround second and third acceleration sensors located in the substrate plane.