A drive device for fuel injection devices (101A, 101B, 101C, 101D) that performs control by applying a current to solenoids (205, 830) of a plurality of fuel injection devices, which open or close fuel flow paths, so as to cause movable valves to be driven so that predetermined quantities of fuel are injected for a set energization time starting from a time where current flows to a particular solenoid until reaching an energization current, comprising a valve closing finish detecting unit configured to acquire a voltage of a solenoid of a fuel injection device (101A, 101B, 101C, 101D), to detect a temporal change thereof using an ECU and to detect a valve closing finish timing when a valve body of the fuel injection device (101A, 101B, 101C, 101D) reaches a valve seat; a valve opening start estimating unit configured to estimate a valve opening start timing of the valve body from a detection value of the valve closing finish detecting unit by multiplying the detection value by a correction constant set in a register of the drive device in advance; an injection time estimating unit configured to obtain an injection time when the valve body is opened, for each individual fuel injection device (101A, 101B, 101C, 101D), from the valve closing finish timing and the valve opening start timing, wherein the set energization time or energization current is adjusted for each individual of the fuel injection devices (101A, 101B, 101C, 101D) so that a divergence value between a target injection quantity determined by the drive device and an estimation value of an injection quantity of the fuel injection device (101A,101B, 101C, 101D) of each cylinder becomes small, the set energization time or energization current adjusted corresponding to a relationship between the injection quantity and a pressure drop detected by a pressure sensor at a predetermined time after the valve opening start timing, the pressure sensor attached to a fuel supply pipe disposed upstream of the plurality of fuel injection devices or any of the plurality of fuel injection devices (101A, 101B, 101C, 101D), wherein each valve opening start timing of each individual fuel injection device (101A, 101B, 101C, 101D) is aligned by varying a turning-on of an injection pulse thereof, and the pressure drop is detected at a time corresponding to half the injection time and a lag time set in the register of the ECU in advance, using the valve opening start timing detected by the valve opening start estimating unit as a start point. a valve closing finish detecting unit configured to acquire a voltage of a solenoid of a fuel injection device (101A, 101B, 101C, 101D), to detect a temporal change thereof using an ECU and to detect a valve closing finish timing when a valve body of the fuel injection device (101A, 101B, 101C, 101D) reaches a valve seat; a valve opening start estimating unit configured to estimate a valve opening start timing of the valve body from a detection value of the valve closing finish detecting unit by multiplying the detection value by a correction constant set in a register of the drive device in advance; an injection time estimating unit configured to obtain an injection time when the valve body is opened, for each individual fuel injection device (101A, 101B, 101C, 101D), from the valve closing finish timing and the valve opening start timing, wherein the set energization time or energization current is adjusted for each individual of the fuel injection devices (101A, 101B, 101C, 101D) so that a divergence value between a target injection quantity determined by the drive device and an estimation value of an injection quantity of the fuel injection device (101A,101B, 101C, 101D) of each cylinder becomes small, the set energization time or energization current adjusted corresponding to a relationship between the injection quantity and a pressure drop detected by a pressure sensor at a predetermined time after the valve opening start timing, the pressure sensor attached to a fuel supply pipe disposed upstream of the plurality of fuel injection devices or any of the plurality of fuel injection devices (101A, 101B, 101C, 101D), wherein each valve opening start timing of each individual fuel injection device (101A, 101B, 101C, 101D) is aligned by varying a turning-on of an injection pulse thereof, and the pressure drop is detected at a time corresponding to half the injection time and a lag time set in the register of the ECU in advance, using the valve opening start timing detected by the valve opening start estimating unit as a start point.