A thin film deposition apparatus includes a vacuum chamber, a substrate supporter disposed in the vacuum chamber to support a target substrate on which a thin film is deposited, and a deposition source that evaporates a deposition material and supplies the evaporated deposition material to the target substrate. The deposition source includes a crucible that includes a deposition material-containing portion to accommodate the deposition material and a first flange at an upper end of the deposition material-containing portion, a spray nozzle that includes a spray portion through which the evaporated deposition material is sprayed and a second flange at a lower end of the spray portion to make contact with the first flange, and a cooling member attached to an outer surface of the first flange and the second flange.