A light-emitting medium including a light-emitting image having a pattern area formed on a substrate by using a first fluorescent ink containing a first fluorescent material, a background area formed on the substrate by using a second fluorescent ink containing a second fluorescent material, and a overcoat layer formed on the first fluorescent material of the pattern area and the second fluorescent material of the background area. The first fluorescent material is made of a fluorescent material which emits light of blue color when UV-A is irradiated, and emits light of red color when UV-C is irradiated. The second fluorescent material is made of a fluorescent material which emits light of blue color or light of a color that is viewed as the same color as the blue color when the UV-A is irradiated, and emits light of green color when the UV-C is irradiated.