An inspecting device includes: an image acquiring unit which acquires a light-emitting surface image as a photographed image of the light-emitting surface; an inspecting unit which sets an inspecting range in a position of the light-emitting surface image in which the failure may appear, detects, from the inspecting range, a bright region which is brighter than a lower limit threshold value, calculates an evaluation value evaluating both the size and luminance of the bright region, and determines the presence or absence of the failure on the basis of the evaluation value; and an output unit which outputs information obtained by the inspecting unit.