A method of sterilization by irradiating with ultraviolet rays with which it is possible to suppress effects on the human body and also to suppress an off odor generated after ultraviolet irradiation. The sterilization method has a step (a) that irradiates ultraviolet rays having a wavelength of 200-230 nm (inclusive) onto the skin of a finger or an arm and a step (b) that applies a topical skin formulation, cosmetic, or aqueous solution containing at least one amino acid or amino acid derivative selected from the amino acid group A to the region of skin irradiated by the ultraviolet rays. (Amino acid group A: valine, leucine, isoleucine, glutamic acid, arginine, serine, aspartic acid, proline, glycine)
