PURPOSE: To provide satisfactory control by relaxing the degradation of controllability caused by arithmetic delay by calculating this time control input by predicting a state amount at the time point of outputting this time control input while using a state amount to be measured before this time and a control input before the last time.

CONSTITUTION: A target value signal 2 is inputted from a position command generating means 1 to a control means 3 and while receiving this signal, the control means 3 outputs an input signal 4 for the input of discrete time control to an output means 5. A predicting means 40 uses a low-order model (temporary delay element x integration element) expressing the characteristic of a controlled system at a low frequency area. The predicting means 40 inputs the input signal 4 (velocity command value) of the last time discrete time control input outputted from the control means 3, receives this time discrete time input signal 12 (position information) outputted from an input means 11, calculates a state predictive signal 14 at the time point of outputting this time control input signal 4 and outputs it to the control means 3. The position control system is constituted by using the position information outputted from this predicting means 40.