Stereomicroscope having a beam splitter device

A stereomicroscope has first and second main beam paths whose spacing defines a stereo base, a microscope axis proceeding through the center of the stereo base parallel to the main beam paths; and an optical beam splitter device for generating an assistant's beam path and a documentation beam path, the assistant's beam path being outcoupled from the first main beam path in a first position of the beam splitter device, and from the second main beam path in a second position, and the documentation beam path being outcoupled from the other main beam path; and the direction of the assistant's beam path in the first position being rotated 180° relative to the assistant's beam path in the second position; and the outcoupled documentation beam path extending, in both positions of the beam splitter device, perpendicular to the outcoupled assistant's beam path.