An inverter control apparatus is provided which controls a resonant soft switching inverter circuit according to the operational principle that the number of the resonant inductors be reduced. When the three phase control signal of the control CPU 5 changes from the (1, 0, 0) state to (0, 0, 1), the drive signal generating device 6 causes a current to flow to the inductor Lr by making the auxiliary switching elements conductive, and when the current I4 flowing to the inductor Lr is the same as the maximum among the currents I1, I2, and I3 flowing through the load, turns OFF the IGBT Q1 and IGBT Q6. Next, the voltage sensors Vs2 and Vs5, which are connected to the IGBTs Q2 and Q5 of the main switching circuit, detect whether or not the voltage across the collector terminal and emitter terminal has become “zero”, and when the outputs Z2 and Z5 of the zero voltage detecting device 8 output the respective logical values “1”, the device signal generating device 6 outputs the switching control signals S2 and S5 that force the IGBTs Q2 and Q5 to conduct, and transit to a stationary condition.