The mounting body includes an annular casing that encloses an area into which a user's living body is inserted, a light emitting element that is provided in the casing and emits light toward the area, and is provided in the casing. An image pickup device that picks up an image of the area when emitting light to obtain an image, a vein pattern acquired in advance, and an authentication circuit that authenticates the user based on the image.装着体は、ユーザの生体が挿入される領域を囲う環状の筐体と、前記筐体に設けられ、前記領域へ向けて光を発する発光素子と、前記筐体に設けられ、前記発光素子が光を発したときに前記領域を撮像して画像を得る撮像素子と、予め取得された静脈パターンと、前記画像とに基づいて前記ユーザを認証する認証回路とを備える。
