A microelectromechanical sensor device having a detection structure comprising: a substrate having a top surface extending in a horizontal plane (xy); a mobile structure (22, 26), comprising an inertial mass suspended above the substrate at a first area of said surface and configured to perform an inertial movement relative to said substrate as a function of a quantity to be detected; a fixed structure (27a, 27b), comprising fixed electrodes suspended above the substrate at said first area of said surface and defining with said mobile structure (22, 26) a capacitive coupling forming at least one sensing capacitor, whose capacitance value is indicative of said quantity to be detected; a single mechanical-anchorage structure for anchoring both of said mobile structure (22, 26) and fixed structure (27a, 27b) to said substrate, at a second area (24") of said surface distinct and separate from said first area; and connection elements (34a-34c), configured to mechanically couple said mobile structure (22, 26) and said fixed structure (27a, 27b) to said single mechanical-anchorage structure, wherein said single mechanical-anchorage structure comprises distinct electrical-coupling regions (32a-32c), mechanically fixed with respect to one another but electrically uncoupled so as to enable definition of separate and distinct conductive paths for electrical biasing of said fixed electrodes (27a-27b) and of said inertial mass, through said electrical-coupling regions (32a-32c) and said connection elements (34a-34c); wherein said connection elements (34a-34c) are each coupled to a respective one of said electrical-coupling regions (32a-32c), characterized by further comprising a first electrical-anchorage structure and a second electrical-anchorage structure, which are distinct and separate from said single mechanical-anchorage structure and are electrically coupled to a first coupling region and, respectively, to a second coupling region of the mechanical-anchorage structure through a first electrical-connection element and a second electrical-connection element; said first and second electrical-anchorage structures (40a, 40b) being fixedly coupled to said substrate and said first and second electrical-connection elements (42a, 42b) being elastic elements constituting a negligible mechanical coupling between said first and second electrical-anchorage structures (40a, 40b) and said first and second coupling regions (32a, 32b) of the mechanical-anchorage structure. a substrate having a top surface extending in a horizontal plane (xy); a mobile structure (22, 26), comprising an inertial mass suspended above the substrate at a first area of said surface and configured to perform an inertial movement relative to said substrate as a function of a quantity to be detected; a fixed structure (27a, 27b), comprising fixed electrodes suspended above the substrate at said first area of said surface and defining with said mobile structure (22, 26) a capacitive coupling forming at least one sensing capacitor, whose capacitance value is indicative of said quantity to be detected; a single mechanical-anchorage structure for anchoring both of said mobile structure (22, 26) and fixed structure (27a, 27b) to said substrate, at a second area (24") of said surface distinct and separate from said first area; and connection elements (34a-34c), configured to mechanically couple said mobile structure (22, 26) and said fixed structure (27a, 27b) to said single mechanical-anchorage structure, wherein said single mechanical-anchorage structure comprises distinct electrical-coupling regions (32a-32c), mechanically fixed with respect to one another but electrically uncoupled so as to enable definition of separate and distinct conductive paths for electrical biasing of said fixed electrodes (27a-27b) and of said inertial mass, through said electrical-coupling regions (32a-32c) and said connection elements (34a-34c); wherein said connection elements (34a-34c) are each coupled to a respective one of said electrical-coupling regions (32a-32c), characterized by further comprising a first electrical-anchorage structure and a second electrical-anchorage structure, which are distinct and separate from said single mechanical-anchorage structure and are electrically coupled to a first coupling region and, respectively, to a second coupling region of the mechanical-anchorage structure through a first electrical-connection element and a second electrical-connection element; said first and second electrical-anchorage structures (40a, 40b) being fixedly coupled to said substrate and said first and second electrical-connection elements (42a, 42b) being elastic elements constituting a negligible mechanical coupling between said first and second electrical-anchorage structures (40a, 40b) and said first and second coupling regions (32a, 32b) of the mechanical-anchorage structure.