Device for evaluating surface state of metal material, device for evaluating visibility of transparent substrate, evaluation program thereof, and computer-readable recording medium recording same

The present invention efficiently and accurately evaluates the surface state of a metal material. This device for evaluating the surface state of a metal material is provided with: an imaging means that pastes the surface of a metal material to at least one surface of a transparent substrate, then removes at least a portion of the metal material by means of etching, and then images, through the transparent substrate, a mark present at the bottom of the transparent substrate; an observation point vs brightness graph creation means that creates an observation point vs brightness graph by measuring the brightness at each observation point along a direction that traverses the observed mark with respect to the obtained image; and a metal-material-surface-state evaluation means that evaluates the visibility of the transparent substrate by means of the slope of the brightness curve arising from the end of the mark across a portion at which the mark is not present, and on the basis of the evaluation results, evaluates the surface state of the metal material. In the observation point vs brightness graph, the metal-material-surface-state evaluation means evaluates visibility using Sv defied in formula (1), and evaluates the surface state of the metal material on the basis of the visibility evaluation results. Sv is valued by (delta B multiply 0.1)/(t1-t2) (1).