An inverter control device for controlling an inverter that generates three-phase alternating current for driving a motor, comprising: a PWM controller configured to execute PWM control based on a torque command value of the motor to cause the inverter to generate the three-phase alternating current; a one-pulse controller configured to execute one-pulse control based on the torque command value to cause the inverter to generate the three-phase alternating current; and a switching controller configured to alternately switch the PWM control and the one-pulse control in a switching period with a preset time length for switching the control of the inverter from the PWM control to the one-pulse control, and configured to control the PWM controller and the one-pulse controller so that the one-pulse control is executed after a lapse of the switching period, wherein the switching controller is configured to control the PWM controller and the one-pulse controller by, in the switching period, gradually increasing a ratio of the period during which one-pulse control is executed; characterized by an output switching unit, wherein the PWM controller is configured to output a PWM signal to the output switching unit; the one-pulse controller is configured to output a rectangular wave signal to the output switching unit; and the switching controller is configured to output switching signals (Usig, Vsig, Wsig) to the output switching unit for instructing the output switching unit for outputting one of the PWM signal and the rectangular wave signal, wherein the PWM signal and the rectangular wave signal are alternately switched in the switching period; and based on the switching signals (Usig, Vsig, Wsg), the output switching unit outputs either the PWM signal or the rectangular wave signal to the inverter. a PWM controller configured to execute PWM control based on a torque command value of the motor to cause the inverter to generate the three-phase alternating current; a one-pulse controller configured to execute one-pulse control based on the torque command value to cause the inverter to generate the three-phase alternating current; and a switching controller configured to alternately switch the PWM control and the one-pulse control in a switching period with a preset time length for switching the control of the inverter from the PWM control to the one-pulse control, and configured to control the PWM controller and the one-pulse controller so that the one-pulse control is executed after a lapse of the switching period, wherein the switching controller is configured to control the PWM controller and the one-pulse controller by, in the switching period, gradually increasing a ratio of the period during which one-pulse control is executed; characterized by an output switching unit, wherein the PWM controller is configured to output a PWM signal to the output switching unit; the one-pulse controller is configured to output a rectangular wave signal to the output switching unit; and the switching controller is configured to output switching signals (Usig, Vsig, Wsig) to the output switching unit for instructing the output switching unit for outputting one of the PWM signal and the rectangular wave signal, wherein the PWM signal and the rectangular wave signal are alternately switched in the switching period; and based on the switching signals (Usig, Vsig, Wsg), the output switching unit outputs either the PWM signal or the rectangular wave signal to the inverter.