In an inverter control apparatus, a phase current calculation section calculates each of phase currents flowing into a motor by using measurement results of a current sensor, and a voltage command generation section calculates three-phase voltage commands by using each of the estimated phase currents. A command modulation section compares the phase voltage commands with each other, to specify a full-on phase or a full-off phase on the basis of the comparison result and then to set the voltage command of the specified phase to a full-on voltage or a full-off voltage, and offsets the voltage commands of the other two phases according to the full-on voltage or the full-off voltage to modulate the voltage commands into voltage commands allowing the line voltage between the other two phases to be kept constant. A PWM signal generation section generates PWM signals by comparing, according to a predetermined rule set in advance, three carrier waves generated by a carrier wave generation section with each of the phase voltage commands modulated by the command modulation section. Accordingly, each of the phase currents can be calculated from a DC input current, so that the efficiency can be improved.