Abstract: An electromagnetic fuel injector comprising a valve body composed of a spherical valve member and a hollow cylindrical slide member which is adapted to slide along a guide hole and the interior of which is a fuel passage. The slide member is provided with openings for passing liquid fuel therethrough at its peripheral wall. A circumferential clearance ranging from 4 to 30 .mu. is provided between the outer surface of the slide member and the inner surface of the guide hole. At least one of the valve member and the slide member which members constitute the valve body is formed of titanium, titanium alloy, ceramic or ferric material. With this arrangement, the slide member may be fabricated without a strictly high accuracy and the mass of the valve body may be reduced, thus increasing the response characteristics of the valve body to the on-off operation of an exciting coil.