To provide a centering device of a measurement object capable of easily making a contact center on a measurement instrument side coincident with centers of contact/electrode of the measurement object even when the outline of the measurement object is changed.

This centering device comprises: a base having a pair of sidewalls facing each other; a plurality of gears journaled to the upper surface of a bottom part of the base by being spaced apart along the side walls; a plurality of flat rails penetrating a plurality of facing rail penetration holes formed on the sidewalls by interposing the gears; and chuck parts alternately formed on one-end sides and the other-end sides of the rails, and holding the measurement object such as a battery, a storage battery and a capacitor. The rail is characterized in that teeth gearing with the gear are formed on its side edge.