To make a data amount of sine wave data used for controlling an induction motor to be small.

The controller of the induction motor is provided with a storage device 2 storing values in a plurality of addresses, a first counter 201 circulating/transiting first to N-th states, a second counter 203 circulating/transiting first to fourth states, an operating part 1 calculating a first calculation value, and a PWM signal generating part 4 generating a first pulse width modulation signal 102 controlling an inverter 7 supplying power to the induction motor 8 and a synchronous interruption signal 103 at a prescribed time pitch. Pulse width of the first pulse width modulation signal is adjusted based on a first calculation value. The first counter transits from one state to a next state in synchronizing with the synchronous interruption signal and the operating part calculates the first calculation value from a value based on the first counter and the second counter. The second counter transits from one state to the next state in synchronizing with transition of the first counter from the N-state to the first state.