A TLC plate allows the separation and detection of target substances on one plate. The TLC plate is made up of a substrate, a separating medium layer stacked on the substrate, and a permeation layer discontinuously stacked on the separating medium layer and allows the permeation of a target substance separated in the separating medium layer, wherein the separating medium layer has a separating property for the target substance and an optical responsiveness for ultraviolet rays, and the permeation layer has an optical responsiveness different from that of the separating medium layer.