Provided are a light-emitting apparatus that can suppress manufacturing cost to a low level and perform light emission with high uniformity using a simple configuration, a calibration coefficient calculation method using the light-emitting apparatus, and a method for calibrating a captured image of an inspection target object. A plurality of light-emitting diodes arranged at equal intervals on the circumference of a virtual circle, and a milky white-colored emission window, which is provided on a top surface portion separated from the light-emitting diodes, has an outer edge that is smaller than the circumference on which the light-emitting diodes are arranged, and allows light of the light-emitting diodes to pass therethrough, are included. The diameter of the virtual circle on which the light-emitting diodes are arranged and a separation distance between the light-emitting diodes and the emission window are set to predetermined distances.
