A new two-axis accelerometer comprising an electric motor-driven rotating body that is distinct from the rotor motor and liked to latter via a flexure zone. The resulting rotating body/flexure zone combination may be of either of two types. In a first type the rotating mass is a concentrated mass and the flexure zone permits the rotating body to perform a transversal parallel shift. In a second type the rotating body is an inertia rotor and the flexure zone is an extension of the rotor shaft that embodies a flexible portion. In either type the rotating body/flexure zone combination has two degrees of flexing freedom with two different flexure coefficients in two mutually perpendicular directions both normal to the electric motor shaft. The accelerometer further comprises a deflector shaft coaxial with the rotor shaft and extending beyond the rotating body in a direction away from the electric motor, and in association with said deflector shaft electro-optical measuring means and processor means for measuring linear acceleration components in said two mutually perpendicular directions. In one of its aspects the two axis accelerometer in accordance with the invention measures only two perpendicular components of the acceleration of a body to which it is attached. By another aspect the two axis accelerometer according to the invention is a multisensor being at one and the same time a two-axis angular rate gyroscope and a two axis accelerometer. By yet another aspect of the invention there is provided a multisensor inertial measurement unit (MIMU) serving for the simultaneous measurement of three angular velocity and three linear acceleration components.