The fuel supply apparatus optimizes the timing of performing the fuel pressure change indication and the fuel injection timing to suppress the real fuel injection amount from being differentiated from the target fuel injection amount even at the time of the fuel pressure being changed, thereby improving fuel consumption. The ECU judges that the fuel pressure change request is generated (“YES” in Step S11), and calculates the change retarding time t1 (Step S12) when the fuel pressure is at the low pressure side, and the ECU determines that the vehicle is in the warming-up state, or that the fuel is at the high temperature. The ECU sets the change timing to avoid the timing of injecting the fuel from overlapping the changing timing of the fuel pressure with reference to the injection timing of the fuel injection control (Step S13).