Abstract: A susceptor situated within an IC circuit fabrication machine has its level and height calibrated using a levelling apparatus which stands on three legs and includes a plurality of suspended level detectors. The susceptor is positioned between the legs under each one of the level detectors. Before susceptor calibration, the levelling apparatus first is calibrated to a known flat surface. The apparatus then is placed within the fabrication machine and the susceptor is moved to a first position. Distal sensing points of each detector are placed in contact with the susceptor surface. Respective level adjustment mechanisms (e.g., screws) of the fabrication machine then are turned to bring adjust the orientation of the susceptor and bring each level detector to a common level indication. The levelling apparatus includes four level detectors aligned along two axes. Once level, the susceptor is raised until level detectors indicate a common desired process position height.