Abstract: A radiation image-converting panel has a stimulable phosphor layer formed on its base. On this stimulable phosphor layer there is formed a transparent protective layer, on which an auxiliary protective layer is pasted by a adhesive so that it can be peeled from the protective layer. In an apparatus for reading out a radiation image from the radiation image-converting panel, an adsorptive cup adsorbed to the base is moved in a subscanning direction and, at the same time, an adsorptive cup adsorbed to the auxiliary protective layer is rotated. Thus, the auxiliary protective layer can be peeled off from the protective layer. While the auxiliary protective layer is peeled, laser beams are caused to scan the stimulable phosphor layer through the protective layer. The phosphorescence emitted by this scanning is detected by a photodetector through a condensing portion.