A radiation image storage panel which is provided with a stimulable phosphor substance layer containing a stimulable phosphor substance formed by a gas phase accumulation method on a support, wherein said stimulable phosphor substance layer is constituted of a columnar crystal structure, and slopes D.sub.1 and D.sub.2 satisfy 0.degree..ltoreq.|D.sub.1-D.sub.2|.ltoreq.40.degree., when acute angles formed by said radiation image storage panel surface and axial lines passing through the center of said columnar crystals, with respect to columnar crystals at arbitrary two points in the radiation image storage panel plane, are designated as slopes of columnar crystals, D.sub.1 and D.sub.2.