PURPOSE: To provide a driving device for control rod driving mechanism in which one inverter power supply having the capacity for one control rod driving mechanism per mechanism is provided to a plurality of control rod driving mechanisms, one invert power supply is combined to one control rod driving mechanism to be driven, the control rod driving mechanisms are successively set in the full-insert position after the full insertion of all control rods.

CONSTITUTION: In a driving device for control rod driving mechanism, a number of control rod driving mechanisms 1 are classified into plural sets, and a control rid switching device 7, an inverter power supply 2 for driving power supply and an inverter controller 3 are provided every set, and this device is further formed of a control device 6 for inputting the control rod position signal from each control rod driving mechanism 1 and outputting control signals to the control rod switching device 7 and the inverter controller 3, and a man machine device 5 for outputting the drive information for control rod to the control device 6 which is an interface with an operator.