A fuel injector is disclosed that has plural nozzle holes with the same cross-sectional shape and can individually set the flow rate of each nozzle hole. The fuel injector includes the plural nozzle holes, a seat section positioned upstream of the nozzle holes, a valve element that closes a valve when brought into contact with the seat section and opens the valve when separated from the seat section, and a circular cone tapered from an upstream end to a downstream end and provided with the seat section and an inlet opening of the nozzle holes. The plural nozzle holes have an identical shape and a shape of a cross-section of each of the nozzle holes is substantially out-of-round, the cross-section being perpendicular to a central axis of each of the nozzle holes. The cross-section of each of the nozzle holes is rotated around the central axis of each of the nozzle holes. A rotation angle of the cross-section is set in such a manner that a relationship between a conical surface of the circular cone and the rotation angle is different among at least two of the nozzle holes.