In a transfer line with mass production capability, calibration systems are included in the process as a separate dedicated station. However, this method is not appropriate in an unattended FMC with flexibility. As the FMC produces vesatile parts with small batch sizes, more flexible calibration systems are required. In this paper, a calibration/inspection system suitable for an unattended turning cell is introduced. The system has functions of dimensional calibration of parts by touch probes, tool wear compensation, and quality monitoring of parts. Furthermore, characteristics of errors in the system are identified and corresponding compensation methodology is suggested. An operation software is developed for efficient use of the system.