Provided is a control device of a fuel injection device which can stabilize a behavior of a valve even when a voltage of a voltage source varies, and can reduce a deviation of an injection amount. The fuel injection device includes a valve and a coil which generates a magnetic attraction force to attract a movable element which drives the valve. A control device applies a predetermined voltage to the coil on the basis of an injection pulse, causes a drive current to flow to the coil until the drive current reaches a maximum current, drives the valve by attracting the movable element, and injects fuel. The drive current flowing to the coil is lowered from the maximum current before the valve reaches a desired maximum lift position, and a constant voltage lower than a predetermined voltage or 0 V is continuously applied to the coil until the valve reaches the desired maximum lift position.