PURPOSE: To accurately detect a metallic film which may generate metal irregularity such as difference in thickness of coating, in the metallic film by artificially preparing a condition capable of observing metal irregularity in thickness of coating.

CONSTITUTION: An inspection apparatus is constituted by providing two light sources 3, 4 for evaluating metal irregularity and one test piece mounting part 5 in a box having one inspection hole 2 provided to the side surface thereof. The light source 3 for evaluating metal irregularity is provided so that the projected light of said light source is reflected by the mirror 6 provided to the proper place in the box 1 and incident to the upper surface of the test piece 8 on the test piece mounting part at an incident angle θ(=30W45°). In addition, the inspection hole 2 is provided so that the reflected lights of the projected light incident from both light sources 3, 4 are passed at each reflected angle θ(=30W60°). By this method, a film which may generate metal irregularity in thickness of coating is accurately detected.