A controller for a conventional synchronous motor is configured to produce desired output characteristics. The controller generates a drive current for based on a current command, has a motor correcting section and a gain adjusting section which output a compensated current command based on the current command according to a compensating transfer function for cancelling a first transfer function showing a first torque response characteristic of the synchronous motor and replacing it with a second transfer function showing a second torque response characteristic, and a current controller which generates a drive current corresponding to the compensated current command.