A three-axis attitude control propulsion device and a flying object like a rocket including the device are provided in which combustion gas for attitude control can be efficiently used. A three-axis attitude control propulsion device 4, having six nozzles has a motor case 6 and three-way discharge changeover valves 10, 10' of a valve plug rotation type enabling a changeover of a flow passage by rotation of the valve plug. Combustion gas 18 is generated by combustion of propellant 8 in the motor case 6. The three-axis attitude control propulsion device is operated so that one or two of the nozzles are opened to thereby discharge the combustion gas 18 and the remaining five or four nozzles are fully closed. Thereby, a three-axis attitude control of pitch control, roll control and yaw control, and control of a neutral state, can be selected.