Provided is a display device manufacturing apparatus and a manufacturing method of a display device. The display device manufacturing apparatus includes: a chamber; a supporter arranged in the chamber and supporting a substrate; an electrode arranged in the chamber so as to face the supporter; a gas supply arranged in the chamber and configured to supply process gas into the chamber; a first baffle arranged at a rim of the supporter and having at least one first through hole; and a second baffle arranged between the first baffle and the chamber and covering the at least one first through hole in a plan view to alter a path of by-products discharged from the chamber.