A sealing apparatus for sealing a first substrate and a second substrate by a sealant includes: a stage which supports the first and second substrates, where the sealant is interposed between the first and second substrates along edges of the first and second substrates, and the stage includes a concave portion defined to correspond to the sealant; and an optical head configured to irradiate light onto the sealant, where the first substrate and the second substrate are fixed together by the light irradiated onto the sealant such that a space surrounded by the sealant between the first substrate and the second substrate is sealed.