An apparatus for manufacturing a display device, comprising a stage, a first electric-field-applying module on a first side of the stage, and including first probe pins, a first light-irradiating module above the stage, and configured to irradiate light to the stage, a first light emission driver configured to transmit a first emission driving signal to the first light-irradiating module, and a signal output unit configured to output a first emission timing signal for setting light irradiation timing of the first light-irradiating module to the first light emission driver, to output a first alignment signal to any one of the first probe pins, and to output a second alignment signal to another one of the first probe pins, wherein the first emission timing signal and the second alignment signal are alternating current (AC) signals, and wherein periods of the first emission timing signal and the second alignment signal are the same.