A tracking device for a modulated data communication light beam, comprising: - a transmitter for transmitting a light beam and a receiver for receiving a light beam or a transmitter/receiver unit adapted to be switched selectively or to transmit and receive simultaneously, and - an optical tracking unit defining an optical axis that either starts from the transmitter or leads to the receiver, and comprising an optical deflection element arranged along said axis, which element is tiltable relative to the transmitter and/or receiver and or the transmitter/receiver unit about a tilt axis extending perpendicularly to the optical axis, for changing the elevation angle under which the light beam enters or exits, and which element is rotatable about a rotation axis that is parallel to the optical axis, either together with the transmitter and/or the receiver and/or the transmitter/receiver unit or relative to the transmitter and/or the receiver and/or the transmitter/receiver unit, for changing the azimuth angle under which the light beam enters or exits, characterized in - that the optical deflection element has a reflective component with a reflection surface and a transmissive component, and - that, for changing the elevation angle by tilting the tilt axis, the optical deflection element is adapted to be operated in a first mode in a first tilt angle range, in which mode the light beam can be deflected by passing through the transmissive component of the optical deflecting element, and to be operated in a second mode in a second tilt angle range, in which mode the light beam can be deflected by reflection from the reflective component of the optical deflection element. t - a transmitter for transmitting a light beam and a receiver for receiving a light beam or a transmitter/receiver unit adapted to be switched selectively or to transmit and receive simultaneously, and - an optical tracking unit defining an optical axis that either starts from the transmitter or leads to the receiver, and comprising an optical deflection element arranged along said axis, which element is tiltable relative to the transmitter and/or receiver and or the transmitter/receiver unit about a tilt axis extending perpendicularly to the optical axis, for changing the elevation angle under which the light beam enters or exits, and which element is rotatable about a rotation axis that is parallel to the optical axis, either together with the transmitter and/or the receiver and/or the transmitter/receiver unit or relative to the transmitter and/or the receiver and/or the transmitter/receiver unit, for changing the azimuth angle under which the light beam enters or exits, characterized in - that the optical deflection element has a reflective component with a reflection surface and a transmissive component, and - that, for changing the elevation angle by tilting the tilt axis, the optical deflection element is adapted to be operated in a first mode in a first tilt angle range, in which mode the light beam can be deflected by passing through the transmissive component of the optical deflecting element, and to be operated in a second mode in a second tilt angle range, in which mode the light beam can be deflected by reflection from the reflective component of the optical deflection element. t