To obtain an operation control apparatus which restrains a torque from being changed when the number of poles of an induction motor is changed over.

A relationship that a maximum torque command value is changed smoothly with reference to a speed of motor rotation ωr and that a maximum torque command value at an arbitrary speed of motor rotation is at the maximum torque or lower of an induction motor 1 or that a maximum torque command value at an arbitrary speed of motor rotation is at the maximum torque or lower of the induction motor 1 corresponding to the speed of motor rotation excluding the bottom part of the maximum torque, of the induction motor 1, which falls during the changeover period of the number of poles is set in advance in a data table part 10a. An input torque command T* and a maximum torque command value T* max corresponding to the speed of motor rotation ωr at this time are read out from the data table 10a by a torque command readout part 10b so as to be compared. A smaller value is selected so as to be used as a new torque command T*', and a vector is controlled.