NOVELTY - A slide mechanism (1) in parallel with a thin-film deposition chamber (40) of a vacuum apparatus maintains a susceptor center shaft part (103). A lateral positioning and supporting mechanism (3) comprises clamp sets (31) fixed to the slide mechanism for clamping at sides of a susceptor (10). Clamp set drivers (33) are each connected to a corresponding clamp set to move the clamp sets simultaneously. Limiters (35) restrict the position of each clamp set and prevent slanting of the susceptor. A clamp set motion module (37) guides each clamp set to move.    USE - Susceptor positioning and supporting device for carrying and elevating substrate in vacuum chamber of vacuum apparatus.    ADVANTAGE - Assures planarity of susceptor carrying substrate while moving up/down inside vacuum chamber. Capable of providing feedback of position and stance of susceptor inside vacuum chamber from outside vacuum chamber. Susceptor penetrates second perforation and is clamped at sides by lateral positioning and supporting mechanism, thus preventing susceptor from slanting inside chamber. Lateral positioning and supporting mechanism and susceptor form closed beam support structure that reduces edge drooping of large-sized susceptor, thus achieving planarity for large-sized susceptors and uniformity for thin-film deposition. Actual position and stance of susceptor can be monitored from outside of chamber, particularly in capacitive coupling plasma (CCP) system application, and parallelism between two electrodes can be improved to obtain uniform plasma density, thus enhancing uniformity of large thin-film deposition processes for fabricating thin film transistor (TFT) liquid crystal display (LCD) and thin-film solar cell and obtaining thin films with excellent quality.    DESCRIPTION OF DRAWING(S) - The drawing shows a sectional view of the susceptor positioning and supporting device.    Slide mechanism (1)    Lateral positioning and supporting mechanism (3)    Susceptor (10)    Clamp sets (31)    Clamp set drivers (33)    Limiters (35)    Thin-film deposition chamber (40)    Susceptor center shaft part (103)