VACUUM PROCESSING APPARATUS AND METHOD FOR SENSING SUBSTRATE IN VACUUM PROCESSING APPARATUS

An apparatus for processing vacuum and a substrate detecting method of the apparatus are provided to detect precisely a substrate by determining whether lights are blocked. An apparatus for processing vacuum includes a chamber(20), a substrate supporting unit(210), and a substrate detecting unit. The chamber includes an inner space and a gate for inputting/outputting a substrate(1). The substrate supporting unit, which is installed in the chamber, is mounted on the substrate. The substrate detecting unit radiates lights into the inner space and blocks the lights when the substrate is mounted on the substrate supporting unit such that the substrate stably mounted on the substrate supporting unit is detected.