A CNG control ECU has a pulse signal determination device determining a pulse width and an output timing of a pulse signal, an electricity control device controlling a supply of electricity to a solenoid, and a current value sensing part sensing a current value of the solenoid. Further, the CNG control ECU has an estimation part estimating an injection start timing and an injection full opening timing on the basis of a differential value of the current value, a first calculation part calculating a first correction part, and a full opening time difference calculation part calculating a full opening time difference. Still further, the CNG control ECU has a correction injection quantity calculation part calculating a correction injection quantity and a second calculation part calculating a second correction value. A correction part makes a correction of adding the first correction value to the output timing and a correction of adding the second correction value to the pulse width.