An apparatus for inspecting an electric component in an inverter circuit has a DC power supply for supplying a direct current to a given position in an inverter circuit, a voltage detector for detecting a voltage at a given position in the inverter circuit, a current detector for detecting a current flowing at a given position in the inverter circuit, a switching circuit for changing positions at which the direct current is supplied from the DC power supply, positions at which the voltage is detected by the voltage detector, and positions at which the current is detected by the current detector, and a controller for outputting a switching signal to the switching circuit. The switching circuit is controlled by the controller to charge an electrolytic capacitor in an inverter circuit with a current from the DC power supply. The electrolytic capacitor is determined as to its quality by determining whether the calculated electrolytic capacitance of the electrolytic capacitor falls within a preset range or not. Each of the transistors of the inverter circuit is determined as to its quality by determining whether an V.sub.CE -I.sub.C curve thereof falls in a preset range or not. The electrolytic capacitor, the transistors, and also diodes connected across the transistors can be determined as to whether they are acceptable or not while they are being connected in the inverter circuit.