This invention relates to a halide-containing stimulable phosphor having
improved moisture resistance and luminance, and a process for producing
the same. The halide-containing stimulable phosphor is characterized in
that, among elements constituting the outermost surface and inside of the
phosphor, there is a difference in composition ratio of a halogen element
between the outermost surface and the inside of the phosphor. A radiation
image conversion panel, which has been improved, for example, in moisture
resistance, luminance and image quality by using the phosphor, and a
process for producing the same are also provided.