To provide an occupant state recognition device which can appropriately recognize an occupant state by determining whether an eye state is an eye-open state or an eye-closed state while taking an individual difference into account.SOLUTION: An occupant state recognition device 100 includes: an eyelid opening recognition unit 11 which recognizes a driver's eyelid opening, and the maximum value and the minimum value of the driver's eyelid opening； an eye state determination unit 12 which determines that an eye state is an eye-open state when the eyelid opening becomes equal to or more than a preset threshold value, and which determines that the eye state is an eye-closed state when the eyelid opening becomes less than the threshold value； and a threshold value re-setting unit 13 which re-sets the threshold value to an opening between the maximum value and the minimum value of the driver's eyelid opening recognized by the eyelid opening recognition unit, when the maximum value does not become equal to or more than the threshold value during a fixed period of time or a fixed number of times of eyelid opening and closing, or when the minimum value does not become equal to or less than the threshold value during the fixed period of time or the fixed number of times of eyelid opening and closing.SELECTED DRAWING: Figure 1【課題】個人差を考慮した開眼状態か閉眼状態かの判定により乗員状態を適切に認識することができる乗員状態認識装置を提供する。【解決手段】乗員状態認識装置１００は、ドライバの瞼の開度と当該ドライバの瞼の開度の最大値及び最小値とを認識する瞼開度認識部１１と、瞼の開度が予め設定された閾値以上となる場合に開眼状態を判定すると共に瞼の開度が閾値未満となる場合に閉眼状態を判定する眼状態判定部１２と、一定時間又は一定の瞼開閉回数の間において最大値が閾値以上とならない場合、あるいは、一定時間又は一定の瞼開閉回数の間において最小値が閾値以下とならない場合、瞼開度認識部により認識された当該ドライバの瞼の開度の最大値と最小値との間の開度となるように閾値を再設定する閾値再設定部１３と、を備える。【選択図】図１
