The MEMS device has a suspended mass supported via a pair of articulation arms by a supporting region. An electrostatic driving system, coupled to the articulation arms, has mobile electrodes and fixed electrodes that are coupled to each other. The electrostatic driving system is formed by two pairs of actuation assemblies, arranged on opposite sides of a respective articulation arm and connected to the articulation arm through connection elements. Each actuation assembly extends laterally to the suspended mass and has an auxiliary arm carrying a respective plurality of mobile electrodes. Each auxiliary arm is parallel to the articulation arms. The connection elements may be rigid or formed by linkages.