A holder is provided for attaching a rigid endoscope to optical component of operating microscope, and provided with a mechanism to adjust the relative position of either the rigid endoscope or the operating microscope or both in vertical direction/plane, horizontal direction/plane and the rotational direction. The said assembly retains all movements of operating microscope including the focusing system of the operating microscope adapted for/applied to the endoscope, which are very much important during surgery. The holder is attached to optical component of the operating microscope and hence endoscope and operating microscope can be used alternately during surgery.
