Abstract: A laser anemometer with several measurement directions is disclosed, in which an incident beam (3) is intercepted by two disks (91, 92) having a common axis which are driven in rotation about this axis. The two disks are provided with transparent and reflecting sectors arranged so that the incident beam successively follows three different paths (3x, 3y, 3z). The axis common to the two disks intersects the axis of the incident beam (3). Mirrors reflect the directed beam in mutually orthogonal directions defining a three-dimensional orthogonal reference system in which the three components of the speed may be successively measured. The anemometer of the invention is particularly suitable for the measurement of the three components of the speed of an aircraft with respect to still air.