The inventive concept provides an edge exposure apparatus for performing an edge exposing process by irradiating a light at an edge region of a substrate. The edge exposure apparatus includes a support unit configured to support the substrate; a light irradiation unit having a light source for irradiating the light on the substrate; and a control unit configured to control an output of the light source, and wherein the control unit comprises: a measurement unit configured to measure illuminance values according to the outputs of the light source; and an output control unit configured to set a reference illuminance value among the measured illuminance values by the measurement unit and to control the output of the light source based on the set reference illuminance value.