Provided is a reference point indicating apparatus comprising at least two link plates, a slide slit formed in each link plate, an indicator configured to be slidable along each slide slit and to be provided at an intersection of a center line of each slide slit, and at least three leg portions configured to be provided on the same circumference centered on the indicator, wherein the indicator is configured to be located on an intersection of a perpendicular bisector of each straight line connecting centers of leg portions adjacent to each other, the leg portions are configured to be contactable with an object 3 by sliding the indicator, the indicator is configured to indicate a reference point of the object in a state where each leg portion is in contact with the object.