A leveling base includes the leveling base including a pedestal, a leveling plate provided to the pedestal via leveling screws such that the leveling is enabled, and a prism unit including a prism having retroreflective characteristics. The prism unit is provided on the leveling plate, the prism unit retro-reflects a light beam entering from a vertically lower side by the prism, a lower through-hole through which a light beam which enters/is reflected to the prism penetrates is provided in the pedestal, and an attachment/detachment portion which enables the attachment/detachment of a predetermined measuring device is provided on an upper surface of the leveling plate.