1. An unevenness inspection method for inspecting presence of unevenness in a panel material, the method comprising: acquiring a plurality of primary images by imaging an entirety of the panel material under inspection on a plurality of levels of condition; creating a plurality of secondary images by processing the plurality of primary images to enhance variation of the primary images; creating a composite image by combining the plurality of secondary images with a prescribed weighting, the prescribed weighting referring to a set of coefficients by which pixel values of the secondary image are multiplied, the set consisting of as many values as the number of the secondary images; and determining the presence of unevenness using the composite image, the prescribed weighting being determined using the panel material for training use having unevenness so that a region having the unevenness can be distinguished from another region not having the unevenness, when the plurality of secondary images are created for the panel material for training use having unevenness and are combined into a composite image.