One of reverse passing parts provided in a substrate passing part
comprises a first holding mechanism and a second holding mechanism. The
first holding mechanism and the second holding mechanism are arranged in
vertically symmetry with respect to a rotary central axis and rotate 180
degrees about the rotary central axis, to replace each other in position.
A transport robot on the loading side passes a substrate to a third
holding mechanism or a fourth holding mechanism at a first vertical
position. The substrate reversed in the reverse passing part is passed to
a transport robot on the unloading side from the third holding mechanism
or the fourth holding mechanism at a second vertical position. Before a
reverse process on the preceding substrate is finished, the transport
robot on the loading side can start the transfer of the following
substrate.