A face horizontal direction measuring unit measures the angle of the face horizontal direction for a face image obtained by an imaging unit. By using information on the radius of the head and information on the shoulder position of the person obtained by the aforementioned measurement, a face vertical displacement measuring unit measures a face displacement in the vertical direction not affected by a head posture. According to the obtained displacement, the face angle in the vertical direction is decided. By using the obtained face direction, the angle of the gaze in the horizontal direction and the eyeball radius are measured. Further, a gaze vertical displacement measuring unit is provided for which measuring the pupil center position against the eyeball center position as the gaze displacement in the vertical direction. This displacement amount is used to measure the gaze angle in the vertical direction.