Abstract: It is an object of the invention to provide a simple disinfecting method for assuring an excellent disinfecting effect. The present method uses a disinfecting liquid in which a hydrogen peroxide is included in an aqueous medium. The disinfecting liquid is accommodated in a suitable container such that the disinfecting liquid accommodated in the container has a depth of 3-10 mm, and the disinfecting liquid in which an object to be disinfected is immersed is irradiated with a light having a wavelength of 280-385 nm, such that the light is incident on the disinfecting liquid at least in a direction of the depth of the disinfecting liquid, so that the object immersed in the disinfecting liquid is disinfected.