To provide a storage phosphor for advantageously applied for the storage phosphor screen or panel which has structured particles containing a dopant or an activator element homogeneously distributed.

The storage phosphor particles suitable for use for a covering layer of a stimulable phosphor screen or panel owing to high relative sensitivity contains, at the surface or in the inner volume of the phosphor particle, as components constituting the phosphor, a matrix component such as CsBr and the dopant or the activator homogeneously incorporated such as Eu, where the particle has preferably an aspect ratio larger than 2:1 but less than 50:1. The aspect ratio is prescribed as a ratio of the two largest sizes, where the sizes are taken in three dimensions perpendicular to each other and one of the two largest sizes is smaller than 10 μm.