To improve response performance of operation in an electromagnetic actuator that is driven with an electromagnetic force of an electromagnet.

A housing 2 of injector 1 of the common-rail type diesel engine includes a movable part 12 displaced on the basis of the electromagnetic force of the electromagnet 11 and an electromagnetic valve 10 supported with a bearing 18 to include a drive axis 13 displaced together with the movable part 12. An orifice hole 17 is opened by driving the drive axis 13 through control of power feeding of the electromagnet 11 and a fuel injection is actualized by lowering fuel pressure of a back pressure control chamber 20. Meanwhile, the orifice hole 17 is closed with a valve 14 by suspending power feeding of the electromagnet 11 and fuel injection is suspended by displacing a needle valve 23 in the direction of an injection hole 3 with the fuel pressure of the back pressure control chamber 20. These movable part 12 and drive axis 13 are formed of a ceramic material and a magnetic material to be magnetized is supported with the movable part 12.