To make it possible for a maintenance person not to periodically perform calibration work of a charge and discharge test device for testing a secondary battery by means of a measuring instrument, and to reduce cost and time for the calibration work and avoid a decline in production efficiency of a secondary battery due to unavailability of the charge and discharge test device during calibration.

A calibration machine unit according to the invention is a calibration machine unit to calibrate a charge and discharge test device used for testing a secondary battery, and is comprised of a housing including a connection terminal arranged the same way as the secondary battery and being the same shape as the secondary battery. The calibration machine unit is characterized by including: a measuring unit which is connected with the charge and discharge test device via the connection terminal instead of the secondary battery, and measures an electrical characteristic of the charge and discharge test device; a radio communication slave unit which performs radio communication with the charge and discharge test device; and a unit secondary battery which supplies power to the measuring unit and the radio communication slave unit.