To simultaneously inject liquid and reformed gas from a fuel injection hole while controlling the quantity of the liquid and the reformed gas by inhibiting the liquid from being excessively injected from the fuel injection hole.

An injector 10 is provided with: an injector body 32 comprising a fuel passage 58 of which the upstream side is a fuel introduction hole 58A in the fuel passage 58 for introducing the reformed gas and of which the downstream side is a fuel injection hole 58B for injecting fuel containing at least reformed gas into a cylinder of an engine, and a liquid passage 68 of which the upstream side is a liquid introduction hole 68A for introducing the liquid and of which the downstream side is a fuel injection hole 68B opened between the fuel introduction hole 58A and the fuel injection hole 58B; a first flow rate control part 34 comprising a first valve sheet 70 and a first valve 72; a second flow rate control part 36 comprising a second valve sheet 76 and a second valve 78; and an actuator 38 comprising a first flow rate control part 34 and a second flow rate control part 36.