A micromechanical mirror includes a mobile mass carrying a mirror element and provided in a body including semiconductor material. A driving structure is coupled to the mobile mass to cause a scanning movement thereof. The driving structure is configured to generate a combination of a two or more sinusoidal resonant modes in the micromechanical mirror at respective resonant frequencies. This combination approximates a scanning pattern of the mobile mass defined by a linear function which may, in particular, be a triangular shaped function.