Disclosed is a method for producing a preserved flower, which enables to keep the original color of a real flower, particularly the subtle gradation in color of the real flower. Also disclosed is a processing solution for use in the method. Specifically disclosed is a method for producing a preserved flower, which comprises immersing a real flower in a processing solution and drying the flower, wherein the processing solution comprises a solution or dispersion containing at least one component selected from a natural oil material oil, a natural resin material, a siloxane, a synthetic resin, a water-addition-reaction-type urethane, a fatty acid ester and a surfactant, wherein the natural oil material is terpin oil, stand oil, whale oil, boiled oil, linseed oil, camellia oil, olive oil, rapeseed oil, a salad oil (a purified plant oil), sesame oil, camphor oil or the like, wherein the natural resin material is rosin, glue, wax, bees wax, rubber, rhus lacquer or the like, and wherein the fatty acid ester is an ester of a saturated or unsaturated fatty acid such as lauric acid, palmitic acid, stearic acid and myristic acid and a lower or polyhydric alcohol.