Internal combustion engine with a fuel injector comprising: an injector body having a fuel outlet; and a spray hole formed in the fuel outlet, wherein said spray hole being geometrically designed to produce a spray of fuel in a predetermined pattern so that substantially 70% or more of a total amount of the spray hits a preselected area on a surface of a head of an intake valve of an engine when the intake valve is closed, the preselected area being one of a first and a second area (28, 29; 28a, 29a) on the surface of the head of the intake valve which are defined by a reference boundary line (27; 27a, 27b) extending through the center of a joint of the head of the intake valve with a stem of the intake valve, the first area (28; 28a) being closer to an intake manifold of the engine, the second area (29; 29a) being closer to an exhaust valve of the engine, the preselected area being the first area (28; 28a), wherein a pattern defined on the surface of the head of the intake valve by the spray of fuel emitted from said spray hole is an oval pattern having a first and a second length, the first length extending in a direction projected by a direction in which the spray of fuel is emitted from the spray hole on the surface of the head of the intake valve, the second length extending perpendicular to the direction of the first length and being longer than the first length, characterized in that a plurality of spray holes is formed in the fuel outlet, and wherein the predetermined pattern of the spray of fuel is established by setting at least one of a layout of the spray holes at the fuel outlet, an angular direction in which a jet of the fuel is outputted from each of the spray holes, a diameter of each of the spray holes, and a pitch between adjacent two of target spots on the preselected area of the head of the intake valve each of which one of the spray holes aims at directing a central portion of the jet of fuel which is the greatest in flow rate of fuel. an injector body having a fuel outlet; and a spray hole formed in the fuel outlet, wherein said spray hole being geometrically designed to produce a spray of fuel in a predetermined pattern so that substantially 70% or more of a total amount of the spray hits a preselected area on a surface of a head of an intake valve of an engine when the intake valve is closed, the preselected area being one of a first and a second area (28, 29; 28a, 29a) on the surface of the head of the intake valve which are defined by a reference boundary line (27; 27a, 27b) extending through the center of a joint of the head of the intake valve with a stem of the intake valve, the first area (28; 28a) being closer to an intake manifold of the engine, the second area (29; 29a) being closer to an exhaust valve of the engine, the preselected area being the first area (28; 28a), wherein a pattern defined on the surface of the head of the intake valve by the spray of fuel emitted from said spray hole is an oval pattern having a first and a second length, the first length extending in a direction projected by a direction in which the spray of fuel is emitted from the spray hole on the surface of the head of the intake valve, the second length extending perpendicular to the direction of the first length and being longer than the first length, characterized in that a plurality of spray holes is formed in the fuel outlet, and wherein the predetermined pattern of the spray of fuel is established by setting at least one of a layout of the spray holes at the fuel outlet, an angular direction in which a jet of the fuel is outputted from each of the spray holes, a diameter of each of the spray holes, and a pitch between adjacent two of target spots on the preselected area of the head of the intake valve each of which one of the spray holes aims at directing a central portion of the jet of fuel which is the greatest in flow rate of fuel.