To provide a modified powder useful as a powder to be incorporated into a cosmetic preparation for preventing the touch from being worsend by the treatment with a regenerated silk fibroin, by conducting the surface treatment by the combination of a treatment with the regenerated silk fibroin and a specified treatment.

This modified powder is obtained by surface-treating a powder with a regenerated silk fibroin and an N-acylated lysine, and the amount of the regenerated silk fibroin used for the surface treatment is not more than one half of the total amount of the surface-treating agents. The modified powder is obtained by, for example, mixing an aqueous slurry of the powder with a desalted silk fibroin solution, adjusting the pH of the obtained mixture to 4, leaving the mixture to stand under stirring, slowly dropping a solution obtained by dissolving an N-acylated lysine in an aqueous sodium hydroxide solution into the mixture under stirring, adjusting the pH to neutrality after the completion of the dropping, filtering the reaction mixture, washing the obtained filter cake with water, drying it, and pulverizing the dried product.