To provide a transmission device for transmitting data for a microscope from an electronic circuit to the microscope and a control device without present normal current and a data cable.

In the transmission device for controlling or inspecting the function of an optical observation unit, e.g. an operation microscope, in an operating state, the microscope (1) is control or inspection of functions e.g., zooming, focusing, a working interval, positioning, tilt, rotation, video or the like is performed between a controlling electronic circuit (3) and a transmission and reception unit (5) for the microscope (1) arranged in the microscope (1) by a transmission and reception unit (4) attached to and fixed to a stand (2) through a bidirectional beam (8). The transmission and reception units (4, 5) transmitting data (7) for controlling the microscope (1) transmit or receive a digital and/or analog electromagnetic beam in the operating state, and are partially shielded in order to avoid undesired radiation.