PROBLEM TO BE SOLVED: To provide an in-facility authentication system capable of continuously authenticating a patient agreeing with a treatment order and a treatment person etc. existing in an identical place in a time zone agreeing with the treatment order.SOLUTION: A first illumination 22 outputs a visible light 22a which includes an illumination ID for authenticating a place in a facility as information. Receiving the visible light 22a, each of light receivers 23-26 which previously has an ID of an object to be mounted transmits an illumination ID based on the visible light 22a and a previously held ID of the object to be mounted as a data. A processing section 30 makes association between the light receivers 23-26 located in an identical illumination area of the first illumination 22 on the basis of the data transmitted from the plural light receivers 23-26 and determines whether a combination of the associated light receivers 23-26 agreeing with the combination of the light receivers based on the treatment order to thereby authenticate the treatment.【課題】処置のオーダーに一致する時間帯に、その処置のオーダーに一致する患者や処置者等が同じ場所に同時に存在することを継続して認証できる施設内認証システムを提供する。【解決手段】第１照明２２が、施設内における場所を特定するための照明ＩＤを情報として含む可視光２２ａを照射する。装着対象ＩＤを予め保持する受光器２３～２６は、可視光２２ａを受光すると、その可視光２２ａに基づく照明ＩＤと、予め保持している装着対象ＩＤをデータとして送信する。処理部３０は、複数の受光器２３～２６から送信されるデータを基に、同一の第１照明２２の照射範囲内に位置する受光器２３～２６を関連付け、関連付けられた受光器２３～２６の組み合わせが、処置オーダーに基づく受光器の組み合わせに一致するか否かを判定することで処置の認証を行う。【選択図】図１
