An orbit attitude control device includes a plurality of nozzles for injecting combustion gas supplied from a combustion chamber, and a control section configured to calculate nozzle opening degree correction values so that a deviation between a detection value of the pressure of the combustion chamber and a command value becomes smaller. The control section is configured to calculate a total correction value so that the deviation between the detection value and the command values becomes smaller. A total value T1 for first group nozzles and a total value T2 for second group nozzles are calculated. The total correction value is distributed to the opening degree correction values for the first group nozzles with a ratio of T2/(T1+T2) and to the opening degree correction values for the second group nozzles with a ratio of T1/(T1+T2).