A transdermal preparation is provided that contains risperidone and/or a pharmaceutically acceptable salt thereof as a drug, and the amount of the drug is 1 to 20 parts by mass based on 100 parts by mass of the total mass of the preparation. The skin permeation rate of the preparation is 0.5 to 30 μg/cm2/hour, and the drug diffusion coefficient of the preparation in the skin is 1.2×10−6 to 10.0×10−6 cm/hour.