The structure enables two-directional sensing of accelerations with compact component dimensions and with minimal cross-axis sensitivity. The rotation mass includes a first frame and a second frame. In one sense direction, the structure employs a combined proof mass of the first frame and the second frame, which improves the signal to noise level achievable with said device dimensions. In the other sense direction, a detection structure with at least two sensing elements is used to detect displacements of the proof mass of the second frame. Due to the specific internal configuration of the detection structure, signal contributions of the sensing elements in the one direction cancel each other.