A fluorescent substrate according to one embodiment of the present disclosure includes: a substrate that is in a rotatable manner; a fluorescent layer disposed in a center of the substrate; and a fixing layer that fixes a portion of a surface on side on which the fluorescent layer is located of the substrate and a portion of a surface on side on which the substrate is located of the fluorescent layer to each other. Thus, in a case where warpage occurs in the substrate due to a stress caused by thermal expansion arising in each of the fluorescent layer and the substrate, it is possible to reduce an amount of displacement of the fluorescent layer.