An inverter device comprising: a three-phase inverter, wherein each phase includes a switching element (Q1, Q3, Q5) on a high potential side and a switching element (Q2, Q4, Q6) on a low potential side; and a controller capable of performing two-phase modulation control on switching of the switching elements (Q1-Q6) between an ON state and an OFF state; the inverter device being characterized by comprising: a power factor computation unit, which is configured to compute a power factor of a load; and a determination unit, which is configured to determine whether the power factor computed by the power factor computation unit is less than a preset threshold value, wherein the inverter device is configured such that if the determination unit determines that the computed power factor is greater than or equal to the threshold value, the controller performs a phase shift, for two phases other than a stop phase in the two-phase modulation control, to either shift central time points of ON periods of one of the two phases relative to the other one of the two phases by 180 degrees or shift central time points of OFF periods of one of the two phases relative to the other one of the two phases by 180 degrees, and if the determination unit determines that the computed power factor is less than the threshold value, the controller supplies the switching elements (Q1-Q6) with ON and OFF control commands to perform the two-phase modulation control without performing the phase shift. a three-phase inverter, wherein each phase includes a switching element (Q1, Q3, Q5) on a high potential side and a switching element (Q2, Q4, Q6) on a low potential side; and a controller capable of performing two-phase modulation control on switching of the switching elements (Q1-Q6) between an ON state and an OFF state; the inverter device being characterized by comprising: a power factor computation unit, which is configured to compute a power factor of a load; and a determination unit, which is configured to determine whether the power factor computed by the power factor computation unit is less than a preset threshold value, wherein the inverter device is configured such that if the determination unit determines that the computed power factor is greater than or equal to the threshold value, the controller performs a phase shift, for two phases other than a stop phase in the two-phase modulation control, to either shift central time points of ON periods of one of the two phases relative to the other one of the two phases by 180 degrees or shift central time points of OFF periods of one of the two phases relative to the other one of the two phases by 180 degrees, and if the determination unit determines that the computed power factor is less than the threshold value, the controller supplies the switching elements (Q1-Q6) with ON and OFF control commands to perform the two-phase modulation control without performing the phase shift. a power factor computation unit, which is configured to compute a power factor of a load; and a determination unit, which is configured to determine whether the power factor computed by the power factor computation unit is less than a preset threshold value, wherein the inverter device is configured such that if the determination unit determines that the computed power factor is greater than or equal to the threshold value, the controller performs a phase shift, for two phases other than a stop phase in the two-phase modulation control, to either shift central time points of ON periods of one of the two phases relative to the other one of the two phases by 180 degrees or shift central time points of OFF periods of one of the two phases relative to the other one of the two phases by 180 degrees, and if the determination unit determines that the computed power factor is less than the threshold value, the controller supplies the switching elements (Q1-Q6) with ON and OFF control commands to perform the two-phase modulation control without performing the phase shift.