A method for positioning a micro-tool (4) comprises: a positioning gauge positioning process (S1) including placing a gauge surface (5d) of a positioning gauge (5) at a needle tip position while the positioning gauge (5) is fixed to a holding part (30), and aligning a mark (5b) provided in the positioning gauge (5) with the optical axis (62a) of an objective lens (62); a positioning gauge focus adjustment process (S2) to focus on the mark (5b) in a state where the positioning gauge (5) has been positioned; and a micro-tool attachment process (S3) including fixing the micro-tool (4) to the holding part (30) after removing the positioning-gauge (5) from the holding part (30).