An apparatus for manufacturing a display device includes: a mask assembly, wherein the mask assembly includes: a mask frame including an open area; a first mask disposed on the mask frame, the first mask including at least one opening; a second mask disposed on the first mask, the second mask including a mesh portion having a mesh shape and a blocking member to shield a portion of the mesh portion; and a first support supporting a display substrate on the second mask and separating the display substrate from the second mask, wherein the blocking member overlaps the opening.