Improved structure of fuel injector adjustable in fuel jet characteristic

A fuel injector is provided which has an improved structure capable of adjusting fuel jet characteristics such as the quantity of fuel to be injected to an engine and a fuel injection time lag after the fuel injector is assembled. The fuel injector includes an air gap (H) adjusting screw (31) and a spring (38) pressure adjusting screw (37). The air gap adjusting screw (31) serves to change an air gap (H) between a stator (34) and an armature (32) of a solenoid valve to adjust the quantity of fuel to a target one. The spring pressure adjusting screw serves to change a spring pressure urging a valve in a spray hole-closing direction to regulate a spray hole open duration, thereby adjusting the fuel injection time lag or the quantity of fuel.