An inverter control device comprising: at least one inverter main circuit (10, 10') to convert, using a plurality of semiconductor switching elements arranged between DC bus lines connected to a positive end and a negative end of a DC power supply respectively, DC power supplied by the DC power supply into three-phase AC power and output the AC power to at least one three-phase synchronous motor (11, 11'); a voltage detector to detect a DC voltage between the DC bus lines; and an inverter control unit to generate a pulse width modulation signal to perform on/off control of each of the plurality of semiconductor switching elements with the DC current and the DC voltage, wherein the inverter control unit sets a calculation period in which the pulse width modulation signal is generated to be twice longer than a calculation time thereof, sets N as an integral number equal to or larger than 1, sets a carrier period of the pulse width modulation signal to be 1/N times as long as the calculation period, performs detection of the DC current detected by the single current detector (14, 14') in a 1/2 calculation period immediately before a calculation start timing for generating the pulse width modulation signal, calculates an output voltage vector based on the detected DC current, and outputs pulse width modulation signals corresponding to the output voltage vector in one calculation period from a 1/2 calculation period after the calculation start timing to 3/2 control calculation periods after the same; and wherein the at least one inverter main circuit (10, 10') comprises a first inverter main circuit and a second inverter main circuit, characterized in that a first three-phase synchronous motor of the at least one three-phase synchronous motor (11, 11') that drives a compressor is driven by AC power supplied from the first inverter main circuit, a second three-phase synchronous motor of the at least one three-phase synchronous motor (11, 11') that drives a blast fan is driven by AC power supplied from the second inverter main circuit; wherein a carrier frequency of the compressor control that is the first inverter control and a carrier frequency of the fan control that is the second inverter control are set to values that can realize synchronization; wherein the carrier frequency of the first inverter control is different from the carrier frequency of the second inverter control, and wherein the inverter control device further comprises: a single current detector (14, 14') to detect a DC current flowing in the DC bus lines between the DC power supply and the inverter main circuit (10, 10'). at least one inverter main circuit (10, 10') to convert, using a plurality of semiconductor switching elements arranged between DC bus lines connected to a positive end and a negative end of a DC power supply respectively, DC power supplied by the DC power supply into three-phase AC power and output the AC power to at least one three-phase synchronous motor (11, 11'); a voltage detector to detect a DC voltage between the DC bus lines; and an inverter control unit to generate a pulse width modulation signal to perform on/off control of each of the plurality of semiconductor switching elements with the DC current and the DC voltage, wherein the inverter control unit sets a calculation period in which the pulse width modulation signal is generated to be twice longer than a calculation time thereof, sets N as an integral number equal to or larger than 1, sets a carrier period of the pulse width modulation signal to be 1/N times as long as the calculation period, performs detection of the DC current detected by the single current detector (14, 14') in a 1/2 calculation period immediately before a calculation start timing for generating the pulse width modulation signal, calculates an output voltage vector based on the detected DC current, and outputs pulse width modulation signals corresponding to the output voltage vector in one calculation period from a 1/2 calculation period after the calculation start timing to 3/2 control calculation periods after the same; and wherein the at least one inverter main circuit (10, 10') comprises a first inverter main circuit and a second inverter main circuit, characterized in that a first three-phase synchronous motor of the at least one three-phase synchronous motor (11, 11') that drives a compressor is driven by AC power supplied from the first inverter main circuit, a second three-phase synchronous motor of the at least one three-phase synchronous motor (11, 11') that drives a blast fan is driven by AC power supplied from the second inverter main circuit; wherein a carrier frequency of the compressor control that is the first inverter control and a carrier frequency of the fan control that is the second inverter control are set to values that can realize synchronization; wherein the carrier frequency of the first inverter control is different from the carrier frequency of the second inverter control, and wherein the inverter control device further comprises: a single current detector (14, 14') to detect a DC current flowing in the DC bus lines between the DC power supply and the inverter main circuit (10, 10').