An apparatus for manufacturing a display device includes a chamber, a heating member disposed inside the chamber to provide a thermal atmosphere inside the chamber, where the heating member includes a first heater and a second heater facing each other, a height adjustment member including an end disposed between the first heater and the second heater, and a driving unit which drives the end of the height adjustment member to move up or down such that the end of the height adjustment member is located at one of a first height and a second height which are different heights between the first heater and the second heater. Each of the first height and the second height is different from a height of a top surface of the first heater, and different from a height of a bottom surface of the second heater facing the top surface of the first heater.