A fuel injection controller includes a transistor downstream of a coil of a fuel injector, two transistors applying a source voltage to an upstream of the coil, a diode refluxing an electric current to the coil from a ground, and a Zener diode provided to promptly consume the counter electromotive force generated in the coil when one of the transistors is turned OFF and the transistor is turned OFF, after an injector-drive-period of the fuel injector is terminated. When a microcomputer measures an injector current “I” decreasing from a time of the termination of an injector-drive-period, a drive control circuit delays an OFF time of the transistor relative to a time of a termination of an injector-drive-period, whereby the injector current “I” decreases gradually.