To provide a method of manufacturing a radiological image converting panel for imparting a radiological image having high durability, high sensitivity and high image quality.

This method of manufacturing the radiological image converting panel, includes a process for forming a stimulable europium activating halogenated cesium type phosphor layer by depositing a substance generated by heating an evaporation source including a europium activating halogenated cesium type phosphor or its raw material on a base board under a decompressing condition, and is composed of the base board and the stimulable europium activating halogenated cesium type phosphor layer formed on the base board, and is characterized in that the deposition is performed under a condition of satisfying a prescribed relational expression in the mole ratio of europium/cesium in the europium activating halogenated cesium type phosphor layer formed on the base board and a base board temperature in deposition.