Provided is an apparatus for processing a substrate. The apparatus includes a chamber, a process unit, and an exhaust member. The chamber has an inner space. The process unit is disposed at the inner space of the chamber and is movable outward from the chamber through a side of the chamber. The process unit includes an exhaust line. The exhaust member is disposed at the chamber. The exhaust member is connected to the exhaust line, and the exhaust member includes a movable exhaust port configured to be moved according to a movement of the process unit.