To perform sufficient reduction of an influence always exercised on a passenger by wind blast even in a state where the posture of a seat body is unstable.

The posture of a wind breaking plate 11, attached to a seat body 4 ejectable from a flying object, based on the seat body 4 is changed by a drive mechanism 12. An ejection seat device comprises a means to detect the posture of the sea body 4; and a means to store a wind breaking effect against a passenger seating the seat body 4 and a relation between the posture of the seat body 4 and the posture of the wind breaking plate 11. According to the detecting posture of the seat body 4 and a stored relation, a drive mechanism 12 is controlled.