An operating microscope (10) includes a base (12) set on a floor surface, a post (14) held for rotation around a vertical rotation axis with respect to the base, a horizontal motion arm (16) held for rotation around a first horizontal rotation axis (O2) with respect to the post, a vertical motion arm (20) held for rotation around a second horizontal rotation axis (O3) with respect to the horizontal motion arm (16), a lens barrel portion (22) supported by the vertical motion arm, an elastic member (40) which is provided between the post and the horizontal motion arm and cancels an angular moment around the horizontal motion arm, a fulcrum (A14) which is provided on the horizontal motion arm and receives a force from the elastic member, and a fulcrum moving mechanism (44) configured to shift the position of the fulcrum in a direction substantially perpendicular to a longitudinal direction of the horizontal motion arm.
