An organic light-emitting layer forming apparatus includes a stage supporting an intermediate product of an organic light emitting device, which includes a substrate, and a pixel defining layer including first openings. The apparatus includes a first mask disposed over the stage and including second openings, and a second mask disposed over the first mask and including third openings. The second mask is movable relative to the first mask between first and second positions. The third openings do not overlap the second openings in the first position while overlapping the second openings in the second position. The apparatus includes an inkjet head unit disposed over the second mask and supplying an organic material to the third openings of the second mask in the first position. The second mask moves to the second position to transfer the organic material through the second openings.