Since a factor affecting an individual difference learning result is reduced or eliminated regardless of a valve body behavior, it is possible to highly accurately detect an individual difference of a fuel injector caused by the valve body behavior and to reliably detect the individual difference even when the fuel injector is replaced. When a valve opening/closing timing of the fuel injector is learned by a learning unit, a unit of interrupting the learning if a predetermined condition is established, a unit of prohibiting the learning of the valve closing timing using the learning unit if a predetermined condition is established, or a unit of prohibiting the learning of the valve opening/closing timing of the fuel injector using the learning unit if a fuel pressure of a common rail supplying a fuel to the plurality of fuel injectors changes by a predetermined value or more within a predetermined time is provided.