A control device for a power converting device which performs PWM on an output from a DC power supply and produces an output of AC power, including: a current controller which converts a given current command value into a voltage command value; a carrier generator which generates a PWM carrier; a PWM generator which generates a PWM signal to be fed to the power converting device according to the voltage command value and the PWM carrier; a frequency controller which effects a change in the frequency of the PWM carrier from the carrier generator; and a current control gain controller which effects a change in the current control gain of the current controller according to the change in the frequency of the PWM carrier. The current control gain of the current controller is changed according to the change in the frequency of the PWM carrier from the carrier generator.