To abate the burden of a control process to be imposed on a controller, and simultaneously to promote a reduction in manhours for adjusting it.

A first correction Δθ1 or a correction for a first command value θ1 to control a pilot injection quantity performs a linear interpolation between the value 'Δθ1H' corresponding to 'NPH' and the value 'Δθ1L' corresponding to the 'NPL', whereby the first correction Δθ1 corresponding to the engine speed is calculated. Likewise, both second and third corrections Δθ2 and Δθ3 or each correction of both second and third command values for controlling a main injection quantity are calculated as well. Thus, since when interpolation calculation on the basis of engine speed is carried out only once, respective corrections Δθ1 to Δθ3 are calculable, so that any burden on a control process to be imposed on a fuel injection controller is reducble. In addition, it is good enough that the correction exists one by one at each command value and engine speed, so that adjusting manhour for the fuel injection controller can be lessened.