PURPOSE: To improve the ratio of success of ejection by controlling an actuator according to the difference between the detected position of a seat body ejected from a flying body and the preset stable position to adjust the force to change the position of the seat body in each direction.

CONSTITUTION: An ejection seat device 1 is provided with a seat body 4 fitted to an ejection guide in a cockpit of an aircraft and a pair of right and left boom storing devices 5 fitted to the seat body 4. A cylindrical boom 7 is stored in the boom storing device 5, and a shutter 11 for adjusting the opening area of each gas ejection port 8 is provided in each boom 7. Each shutter 11 is connected to an individual actuator 13 through a wire 12, the opening area of the gas ejection port 8 is changed, and the stress to change the position of the seat body 4 in the pitch, yaw and roll direction is generated. Each actuator 13 is connected to a control device 15 through a drive circuit 14, and the control device 15 is connected to a position detecting sensor 16 of the seat body 4.