A radiation detecting apparatus having: a substrate; a phosphor layer which is formed on a principal plane of the substrate and converts a wavelength of a radiation; and a phosphor protective member including a phosphor protective layer which covers the phosphor layer and is adhered to the substrate, wherein the phosphor protective layer is made of a hot melt resin and an upper surface and a side surface of the phosphor layer and at least a part of at least one side surface of the substrate are covered with the phosphor protective layer. Thus, a moisture-proofing effect for penetration of the moisture from an interface between the phosphor layer and the substrate on the side surface side of the substrate can be improved. Further, by using the hot melt resin for the phosphor protective layer, simplification of manufacturing steps, remarkable reduction in the number of working steps, and remarkable reduction in costs of a product can be accomplished.