1. An eye open/close recognizing apparatus comprising: image obtaining unit that obtains an image of a face of a person subjected to image pickup; facial-expression estimating unit that estimates a facial expression of the person subjected to image pickup based on the image; eye-open-level obtaining unit that obtains an eye open level of the person subjected to image pickup based on the image; threshold setting unit that sets a threshold to be low when it is determined that facial expression estimated by the facial-expression estimating unit indicates that an awakening level is high, and sets the threshold to be high when it is determined that the facial expression estimated by the facial-expression estimating unit indicates that the awakening level is low; and eye open/close determining unit which determines that an eye of the person subjected to image pickup is opened upon determination that the eye open level exceeds the threshold, and which determines that the eye of the person subjected to image pickup is closed upon determination that the eye open level does not exceed the threshold.