A radiation image conversion panel that has a phosphor layer. The phosphor layer contains a binding agent, a phosphor particle, and at least aryl carboxylic acid or alicyclic carboxylic acid, expressed by the following general Formula: R--R.sup.1--COOX, or R--COOX in which R represents (1) an aryl group; (2) an aryl group, replaced with an alkyl group whose number of carbons is 1 to 5, a hydroxyl group, a carboxylic acid group, or a halogen group; (3) a hydroaryl group; or (4) a hydroaryl group (alicyclic group), replaced with an alkyl group whose number of carbons is 1 to 5, a hydroxyl group, or a halogen group; R.sup.1 is a hydrocarbon radical whose number of carbons is 1 to 12; and X represents a hydrogen atom, alkaline metal, or --N.sup.+ (R.sup.2).sub.4 (where R.sup.2 represents an alkyl group whose number of carbons is 2 or less).