A thin film deposition apparatus that forms a thin film on a substrate includes: a deposition source that discharges a deposition material; a deposition source nozzle unit that is disposed at a side of the deposition source and includes a plurality of deposition source nozzles; a patterning slit sheet that is disposed opposite to the deposition source nozzle unit and includes a plurality of patterning slits; and a blocking member that is disposed between the substrate and the deposition source, wherein the thin film deposition apparatus is separated from the substrate by a predetermined distance, the substrate is moved relative to the thin film deposition apparatus, and the blocking member is moved along with the substrate to screen at least one portion of the substrate.