An organic layer deposition apparatus including: a deposition source configured to discharge a deposition material; a deposition source nozzle unit arranged at a side of the deposition source and including a plurality of deposition source nozzles; a patterning slit sheet facing the deposition source nozzle unit and including a plurality of patterning slits, the patterning slit sheet being smaller than the substrate in at least one of a first direction or a second direction perpendicular to the first direction; a blocking member configured to be disposed between the substrate and the deposition source to block at least a portion of the substrate; and a heating member on the blocking member and configured to heat the blocking member, and the substrate is spaced apart from the organic layer deposition apparatus by a predetermined distance, and the substrate or the organic layer deposition apparatus is movable relative to the other.