A medicinal active ingredient is provided which is useful for the treatment or prevention of inflammatory diseases, diseases caused by lipid oxidation, retinochoroidal disorders. Aphenylimidazole derivative represented by Formula (IB) or a salt thereof is provided. A therapeutic medicine or preventive medicine is provided for inflammatory diseases, diseases caused by lipid oxidation, or retinochoroidal disorders, the medicine including at least one selected from the phenylimidazole derivative, a salt thereof, and metabolites thereof as an active ingredient. In Formula (IB), R 1a represents an alkyl group etc., R 2 represents an amino group etc., R 3 represents a halogen atom, an alkyl group etc., R 4 represents a cyano group etc., R 5 represents an alkyl group etc., and R 6 represents an alkyl group etc.
