Patent ID: 7724428

Claim:
An operating microscope comprising: a base set on a floor surface; a post held for rotation around a vertical rotation axis with respect to the base; a horizontal motion arm held for rotation around a first horizontal rotation axis with respect to the post; a vertical motion arm held for rotation around a second horizontal rotation axis with respect to the horizontal motion arm; a lens barrel portion supported by the vertical motion arm; an elastic member which is axially expandable and contractable and which is provided between the post and the horizontal motion arm and cancels an angular moment around the horizontal motion arm; a fulcrum which is provided on the horizontal motion arm and receives a force from an end of the elastic member; and a floor tilt correcting mechanism configured to shift the position of the fulcrum in a direction substantially perpendicular to a longitudinal direction of the horizontal motion arm and in a direction substantially perpendicular to the first horizontal rotation axis.