An inverter apparatus comprising: a first capacitor connected in parallel with a DC power source such that one end of the first capacitor is connected to a voltage E1 of the DC power source and the other end of the first capacitor is connected to ground; a first switch group that is connected in parallel with the DC power source and the first capacitor and includes a first switch and a second switch connected in series such that one end of the first switch is connected to the voltage E1 of the DC power source and one end of the second switch is connected to ground; a second capacitor that has one end thereof connected to a first connection point between the first switch and the second switch; a second switch group that is connected in parallel with the second capacitor and includes a third switch and a fourth switch that are connected in series such that one end of the third switch is connected to the first connection point and one end of the fourth switch is connected to the other end of the second capacitor; a switch control section that is configured to control an ON/OFF state of the first switch, the second switch, the third switch, and the fourth switch to convert DC voltage from the DC power source into AC voltage and output the AC voltage from a second connection point between the third switch and the fourth switch; and a smoothing circuit that is connected at one end to the second connection point, is connected at another end to ground, and is configured to normalize a pulse waveform of the AC voltage, characterized in that, during a first interval defining a half-period in which a reference AC voltage is positive, the switch control section is configured to perform PWM control of the first switch, the second switch, the third switch and the fourth switch such that the first switch and the second switch are turned ON and OFF in an alternating manner based on a first voltage command value, and the third switch and the fourth switch are turned ON and OFF in an alternating manner based on a second voltage command value, wherein, during a second interval defining a half-period in which the reference AC voltage is negative, the switch control section is configured to perform PWM control of the third switch and the fourth switch such that the third switch and the fourth switch are turned ON and OFF in an alternating manner while the switch control section is configured to turn the first switch OFF and to turn the second switch ON, wherein the first voltage command value is expressed by the expression v 1 ref = { 2 2 V S cos θ − π 2 < θ < π 2 ⋯ INTERVAL I 0 − π < θ < − π 2 π 2 < θ < π} ⋯ INTERVAL II and wherein the second voltage command value is expressed by the expression v 2 ref = { − 2 V S cos θ − π 2 < θ < π 2 ⋯ INTERVAL I 2 V S cos θ − π < θ < − π 2 π 2 < θ < π} ⋯ INTERVAL II. a first capacitor connected in parallel with a DC power source such that one end of the first capacitor is connected to a voltage E1 of the DC power source and the other end of the first capacitor is connected to ground; a first switch group that is connected in parallel with the DC power source and the first capacitor and includes a first switch and a second switch connected in series such that one end of the first switch is connected to the voltage E1 of the DC power source and one end of the second switch is connected to ground; a second capacitor that has one end thereof connected to a first connection point between the first switch and the second switch; a second switch group that is connected in parallel with the second capacitor and includes a third switch and a fourth switch that are connected in series such that one end of the third switch is connected to the first connection point and one end of the fourth switch is connected to the other end of the second capacitor; a switch control section that is configured to control an ON/OFF state of the first switch, the second switch, the third switch, and the fourth switch to convert DC voltage from the DC power source into AC voltage and output the AC voltage from a second connection point between the third switch and the fourth switch; and a smoothing circuit that is connected at one end to the second connection point, is connected at another end to ground, and is configured to normalize a pulse waveform of the AC voltage, characterized in that, during a first interval defining a half-period in which a reference AC voltage is positive, the switch control section is configured to perform PWM control of the first switch, the second switch, the third switch and the fourth switch such that the first switch and the second switch are turned ON and OFF in an alternating manner based on a first voltage command value, and the third switch and the fourth switch are turned ON and OFF in an alternating manner based on a second voltage command value, wherein, during a second interval defining a half-period in which the reference AC voltage is negative, the switch control section is configured to perform PWM control of the third switch and the fourth switch such that the third switch and the fourth switch are turned ON and OFF in an alternating manner while the switch control section is configured to turn the first switch OFF and to turn the second switch ON, wherein the first voltage command value is expressed by the expression v 1 ref = { 2 2 V S cos θ − π 2 < θ < π 2 ⋯ INTERVAL I 0 − π < θ < − π 2 π 2 < θ < π} ⋯ INTERVAL II and wherein the second voltage command value is expressed by the expression v 2 ref = { − 2 V S cos θ − π 2 < θ < π 2 ⋯ INTERVAL I 2 V S cos θ − π < θ < − π 2 π 2 < θ < π} ⋯ INTERVAL II.