Direct injection fuel injector and internal combustion engine mounting the same

In a spray characteristic in a direct injection system gasoline engine use electromagnetic system fuel injector (1), to a piston cavity a mixture of fuel and air having a combustible concentration is converged and making rich the mixture having the combustible concentration at a side of ignition plug (65), then an ignition performance is improved and making thin the mixture of fuel and air to a piston direction a combustion performance is improved, namely it is necessary to generate a flat inclined spray. A part of a wall face for forming the injection hole (8) at an outlet portion of the injector is formed with V groove according to two inclination faces with optional angles against a center axial line of the injection hole (8) or a substantially recess shape step-wise rectangular groove having different cut-off depths.