In a center injection type of direct injection engine, since it has an ignition plug and an injector arranged in proximity, there occurs the problem that a sprayed liquid fuel directly strikes the ignition plug and causes the plug to misfire. A notch is to be provided at a portion of the injector end so as to form a coarse-grained portion and a dense portion in sprays of fuel, and the injector is disposed so that the coarse-grained portion is directed towards the ignition plug. It is possible to avoid the misfiring of the ignition plug and thus prolong the life of the plug, by preventing a liquid fuel from directly striking the plug.