To improve a delay time of a driving current to improve the attitude controlling accuracy for a satellite by applying a different voltage to a valve driving part for opening and closing a thruster for a predetermined time by an on-off circuit for supplying the driving current to the thruster.

A drive instruction signal 6 input to a gas jet thruster device is input to a timing producing circuit 13. On this occasion, the timing producing circuit 13 outputs a signal while dividing the signal into a signal remaining a pulse width and a signal regarding a remained time as a pulse width for a specific time from the timing of the pulse rising of the drive instruction signal 6. The divided signals are respectively input to switching circuits 12a, 12b. The switching circuits 12a, 12b execute the on/off control of a DC voltage 11a of high voltage value and an ordinary voltage 11b, produced by a DC/DC converter 10a. Whereby an electric current flows. The electric currents flowing from two voltage sources are not simultaneously switched on.